Communication device, communication method, and program

ABSTRACT

A communication device includes: a communication unit that performs wireless communication; and a control unit ( 103 ) that performs control so that a plurality of synchronization signals is patterned and arranged in regions to which resources of the wireless communication are allocated and is transmitted to another terminal device, the plurality of synchronization signals being associated with each of a plurality of beams allocated to be available for inter-device communication between different terminal devices, in which the control unit ( 103 ) performs control so that a pattern in which the plurality of synchronization signals is arranged is switched according to a predetermined condition.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is based on PCT filing PCT/JP2019/036110, filedSep. 13, 2019, which claims priority to JP 2018-181282, filed Sep. 27,2018, the entire contents of each are incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to a communication device, acommunication method, and a program.

BACKGROUND ART

A wireless access manner and a wireless network (hereinafter, referredto as “long term evolution (LTE)”, “LTE-advanced (LTE-A)”, “LTE-advancedpro (LTE-A Pro)”, “new radio (NR)”, “new radio access technology(NRAT)”, “evolved universal terrestrial radio access (EUTRA)”, or“further EUTRA (FEUTRA)”) of cellular mobile communication have beenstudied in the 3rd Generation Partnership Project (3GPP). Note that inthe following description, LTE includes LTE-A, LTE-A Pro, and EUTRA, andNR includes NRAT and FEUTRA. In the LTE and the NR, a base stationdevice (base station) is also called an evolved NodeB (eNodeB), and aterminal device (mobile station, mobile station device, or terminal) isalso called user equipment (UE). The LTE and the NR are cellularcommunication systems in which a plurality of areas covered by the basestation device is arranged in a cell shape. A single base station devicemay manage a plurality of cells.

In the LTE, various types of communication in a vehicle(vehicle-to-anything (V2X) communication) such as vehicle-to-vehicle(V2V) communication, vehicle-to-pedestrian (V2P) communication,vehicle-to-infrastructure/network (V2I/N), and the like, have beensupported. The V2X in the LTE supports use cases such as drivingassistance or autonomous driving, a warning to a pedestrian, and thelike. A sidelink (also referred to as device to device (D2D)communication) is used in order to support the V2X.

Moreover, in the NR, in addition to supporting a V2X use case of theLTE, it has been required to support use cases with higher requirements,such as vehicles platooning, extended sensors, advanced driving, remotedriving, or the like. In order to support these use cases, a higherthroughput, lower latency, and higher reliability have been required,such that an operation in a millimeter wave such as a 60 GHz band or thelike has also been studied. Details of the V2X in the NR are disclosedin Non-Patent Document 1.

CITATION LIST Non-Patent Document

-   Non-Patent Document 1: RP-181429, Vodafone, “New SID: Study on NR    V2X,” 3GPP TSG RAN Meeting #80, La Jolla, USA, Jun. 11-14, 2018.

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

Meanwhile, the millimeter wave has significant radio wave attenuation,such that communication using the millimeter wave may require atechnology called beamforming, which is also similar for V2Xcommunication (for example, V2V communication) of the NR. Furthermore,in the V2X communication of the NR, there may be a restriction called aso-called half duplex (HD). Due to such a factor, in the V2Xcommunication of the NR, a situation in which it takes time forestablishment of communication (setup for connection), such thatcommunication becomes unstable can be assumed.

Therefore, the present disclosure proposes a technology capable ofrealizing establishment of communication between terminals in whichapplication of NR is assumed, in a more suitable manner.

Solutions to Problems

According to the present disclosure, there is provided a communicationdevice including: a communication unit that performs wirelesscommunication; and a control unit that performs control so that aplurality of synchronization signals is patterned and arranged inregions to which resources of the wireless communication are allocatedand is transmitted to another terminal device, the plurality ofsynchronization signals being associated with each of a plurality ofbeams allocated to be available for inter-device communication betweendifferent terminal devices, in which the control unit performs controlso that a pattern in which the plurality of synchronization signals isarranged is switched according to a predetermined condition.

Furthermore, according to the present disclosure, there is provided acommunication device including: a communication unit that performswireless communication; and a control unit performs control so that aplurality of synchronization signals transmitted from another terminaldevice and associated with each of a plurality of beams allocated to beavailable for inter-device communication between different terminaldevices is received, in which the control unit performs control so thatinformation regarding switching of a pattern in which the plurality ofsynchronization signals is arranged in regions to which resources of thewireless communication are allocated is acquired from the anotherterminal device, in a case where the pattern is switched.

Furthermore, according to the present disclosure, there is provided acommunication method executed by a computer, including: performingwireless communication; performing control so that a plurality ofsynchronization signals is patterned and arranged in regions to whichresources of the wireless communication are allocated and is transmittedto another terminal device, the plurality of synchronization signalsbeing associated with each of a plurality of beams allocated to beavailable for inter-device communication between different terminaldevices; and performing control so that a pattern in which the pluralityof synchronization signals is arranged is switched according to apredetermined condition.

Furthermore, according to the present disclosure, there is provided acommunication method executed by a computer, including: performingwireless communication; performing control so that a plurality ofsynchronization signals transmitted from another terminal device andassociated with each of a plurality of beams allocated to be availablefor inter-device communication between different terminal devices isreceived; and performing control so that information regarding switchingof a pattern in which the plurality of synchronization signals isarranged in regions to which resources of the wireless communication areallocated is acquired from the another terminal device, in a case wherethe pattern is switched.

Furthermore, according to the present disclosure, there is provided aprogram for causing a computer to execute the following steps of:performing wireless communication; performing control so that aplurality of synchronization signals is patterned and arranged inregions to which resources of the wireless communication are allocatedand is transmitted to another terminal device, the plurality ofsynchronization signals being associated with each of a plurality ofbeams allocated to be available for inter-device communication betweendifferent terminal devices; and performing control so that a pattern inwhich the plurality of synchronization signals is arranged is switchedaccording to a predetermined condition.

Furthermore, according to the present disclosure, there is provided aprogram for causing a computer to execute the following steps of:performing wireless communication; performing control so that aplurality of synchronization signals transmitted from another terminaldevice and associated with each of a plurality of beams allocated to beavailable for inter-device communication between different terminaldevices is received; and performing control so that informationregarding switching of a pattern in which the plurality ofsynchronization signals is arranged in regions to which resources of thewireless communication are allocated is acquired from the anotherterminal device, in a case where the pattern is switched.

Furthermore, according to the present disclosure, there is provided acommunication device including: a communication unit that performswireless communication; and a control unit that independently controls afirst transmission timing of first communication with destinationdesignation and a second transmission timing of second communicationwithout destination designation among inter-device communication betweendifferent terminal devices.

Furthermore, according to the present disclosure, there is provided acommunication method executed by a computer, including: performingwireless communication; and independently controlling a firsttransmission timing of first communication with destination designationand a second transmission timing of second communication withoutdestination designation among inter-device communication betweendifferent terminal devices.

Furthermore, according to the present disclosure, there is provided aprogram for causing a computer to execute the following steps of:performing wireless communication; and independently controlling a firsttransmission timing of first communication with destination designationand a second transmission timing of second communication withoutdestination designation among inter-device communication betweendifferent terminal devices.

Effects of the Invention

As described above, according to the present disclosure, a technologycapable of realizing establishment of communication between terminals inwhich application of NR is assumed, in a more suitable manner isprovided.

Note that the effect described above is not necessarily restrictive, andany effect set forth in the present specification or other effects thatcan be grasped from the present specification may be accomplishedtogether with or instead of the effect described above.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is an explanatory diagram for describing an outline of sidelinkcommunication according to an embodiment of the present disclosure.

FIG. 2 is a schematic block diagram illustrating a configuration of abase station device according to the same embodiment.

FIG. 3 is a schematic block diagram illustrating a configuration of aterminal device according to the same embodiment.

FIG. 4 is an explanatory diagram for describing an example of dynamicresource pool allocation of a sidelink.

FIG. 5 is an explanatory diagram for describing another example ofdynamic resource pool allocation of a sidelink.

FIG. 6 is an explanatory diagram for describing another example ofdynamic resource pool allocation of a sidelink.

FIG. 7 is an explanatory diagram for describing another example ofdynamic resource pool allocation of a sidelink.

FIG. 8 is an explanatory diagram for describing another example ofdynamic resource pool allocation of a sidelink.

FIG. 9 is an explanatory diagram for describing an outline ofdevice-to-device (D2D).

FIG. 10 is an explanatory diagram for describing an outline ofvehicle-to-vehicle (V2V) communication of new radio (NR).

FIG. 11 is an explanatory diagram for describing an outline of a halfduplex (HD) restriction.

FIG. 12 is an explanatory diagram for describing an example of aconfiguration of a sidelink synchronization signal (SLSS) block.

FIG. 13 is an explanatory diagram for describing an outline of anexample of an arrangement of the SLSS blocks.

FIG. 14 is an explanatory diagram for describing an example of anarrangement pattern of the SLSS blocks.

FIG. 15 is an explanatory diagram for describing another example of anarrangement pattern of the SLSS blocks.

FIG. 16 is an explanatory diagram for describing an example of a settingmethod of an SLSS block set.

FIG. 17 is an explanatory diagram for describing another example of asetting method of an SLSS block set.

FIG. 18 is an explanatory diagram for describing a method of providingnotification of a use situation of the SLSS block by a bitmap.

FIG. 19 is a sequence diagram illustrating an example of a procedurerelated to establishment of unicast communication via a sidelink.

FIG. 20 is a sequence diagram illustrating another example of aprocedure related to establishment of unicast communication via asidelink.

FIG. 21 is an explanatory diagram for describing an example of arelationship between a geographical position of the terminal device anda zone ID.

FIG. 22 is a diagram illustrating an example of a relationship betweenthe zone ID and an allocated frequency band.

FIG. 23 is a diagram illustrating an example of a relationship among azone ID, a beam ID, and a frequency band allocated to transmission.

FIG. 24 is a diagram illustrating an example of a relationship between abeam ID and a frequency band allocated to transmission.

FIG. 25 is a diagram illustrating another example of a relationshipbetween a beam ID and a frequency band allocated to transmission.

FIG. 26 is a block diagram illustrating a first example of a schematicconfiguration of an eNB.

FIG. 27 is a block diagram illustrating a second example of a schematicconfiguration of an eNB.

FIG. 28 is a block diagram illustrating an example of a schematicconfiguration of a smartphone.

FIG. 29 is a block diagram illustrating an example of a schematicconfiguration of a car navigation device.

MODE FOR CARRYING OUT THE INVENTION

Hereinafter, preferred embodiments of the present disclosure will bedescribed in detail with reference to the accompanying drawings. Notethat in the present specification and the drawings, components havingsubstantially the same functional configuration will be denoted by thesame reference numerals, and an overlapping description thereof willthus be omitted.

Note that a description will be given in the following order.

1. Introduction

2. Technical problem

3. Technical feature

4. Application example

-   -   4.1. Application example related to base station    -   4.2. Application example related to terminal device

5. End

1. Introduction

Hereinafter, preferred embodiments of the present disclosure will bedescribed in detail with reference to the accompanying drawings. Notethat in the present specification and the drawings, components havingsubstantially the same functional configuration will be denoted by thesame reference numerals, and an overlapping description thereof willthus be omitted. Furthermore, unless otherwise stated, technologies,functions, methods, configurations, procedures, and all otherdescriptions described below can be applied to long term evolution (LTE)and new radio (NR).

<Wireless Communication System in Present Embodiment>

In the present embodiment, a wireless communication system includes atleast a base station device 1 and a terminal device 2. The base stationdevice 1 can accommodate a plurality of terminal devices. The basestation device 1 can be connected to another base station device bymeans of an X2 interface. Furthermore, the base station device 1 can beconnected to an evolved packet core (EPC) by means of an S1 interface.Moreover, the base station device 1 can be connected to a mobilitymanagement entity (MME) by the means of an S1-MME interface, and can beconnected to a serving gateway (S-GW) by the means of an S1-U interface.The S1 interface supports a many-to-many connection between the MMEand/or S-GW and base station device 1. Furthermore, in the presentembodiment, the base station device 1 and the terminal device 2 supportLTE and/or NR, respectively.

<Outline of Sidelink Communication in Present Embodiment>

FIG. 1 is an explanatory diagram for describing an outline of sidelinkcommunication according to the present embodiment. As a certain usecase, for example, there is a case where two or more terminal devices 2exist inside a cell 3 configured by the base station device 1 andsidelink communication is performed between the terminal devices 2.Furthermore, as another use case, for example, there is a case wheresidelink communication is performed between two or more terminal devices2 in a situation where at least one of the two or more terminal devices2 exists inside a cell 3 configured by the base station device 1 and theother terminal device 2 exists outside the cell 3. Moreover, theterminal device 2 existing inside the cell 3 can perform relay ofcommunication between the base station device 1 and the terminal device2 existing outside the cell 3 by performing communication with the basestation device 1.

Note that it can be said that a state in which the terminal device 2exists inside the cell 3 is a state in which a quality of a downlinksignal received by the terminal device 2 from the base station device 1is equal to or higher than a predetermined reference. Furthermore, itcan be said that a state in which the terminal device 2 exists insidethe cell 3 is a state in which a probability that a predetermineddownlink channel received by the terminal device 2 from the base stationdevice 1 can be decoded is equal to or higher than a predeterminedprobability. In other words, it can be said that a state in which theterminal device 2 exists outside the cell 3 is a state in which aquality of a downlink signal received by the terminal device 2 from thebase station device 1 is below a predetermined reference. Furthermore,it can be said that a state in which the terminal device 2 existsoutside the cell 3 is a state in which a probability that apredetermined downlink channel received by the terminal device 2 fromthe base station device 1 can be decoded is not equal to or higher thana predetermined probability.

Hereinafter, in the present embodiment, two terminal devices thatperform transmission and reception by sidelink communication will alsobe referred to as a first terminal device and a second terminal device.In particular, in the present embodiment, a terminal device thatreceives information regarding sidelink communication from a basestation device and transmits a sidelink control channel may be referredto as a first terminal device and the other terminal device may bereferred to as a second terminal device.

<Configuration Example of Base Station Device in Present Embodiment>

FIG. 2 is a schematic block diagram illustrating a configuration of thebase station device 1 according to the present embodiment. Asillustrated in FIG. 2, the base station device 1 includes an upper layerprocessing unit 101, a control unit 103, a reception unit 105, atransmission unit 107, and a transmission/reception antenna 109.Furthermore, the reception unit 105 includes a decoding unit 1051, ademodulating unit 1053, a demultiplexing unit 1055, a wireless receivingunit 1057, and a channel measuring unit 1059. Furthermore, thetransmission unit 107 includes a coding unit 1071, a modulating unit1073, a multiplexing unit 1075, a wireless transmitting unit 1077, and adownlink reference signal generating unit 1079.

As described above, the base station device 1 can support one or moreradio access technologies (RATs). Some or all of respective unitsincluded in the base station device 1 illustrated in FIG. 2 may beindividually configured according to the RAT. For example, the receptionunit 105 and the transmission unit 107 are individually configured inLTE and NR. Furthermore, in an NR cell, some or all of the respectiveunits included in the base station device 1 illustrated in FIG. 2 may beindividually configured according to a parameter set regarding atransmission signal. For example, in the NR cell, the wireless receivingunit 1057 and the wireless transmitting unit 1077 may be individuallyconfigured according to the parameter set regarding the transmissionsignal.

The upper layer processing unit 101 performs processing of a mediumaccess control (MAC) layer, a packet data convergence protocol (PDCP)layer, a radio link control (RLC) layer, and a radio resource control(RRC) layer. Furthermore, the upper layer processing unit 101 generatescontrol information for controlling the reception unit 105 and thetransmission unit 107, and outputs the control information to thecontrol unit 103.

The control unit 103 controls the reception unit 105 and thetransmission unit 107 on the basis of the control information from theupper layer processing unit 101. The control unit 103 generates controlinformation for the upper layer processing unit 101 and outputs thecontrol information to the upper layer processing unit 101. The controlunit 103 inputs a decoded signal from the decoding unit 1051 and achannel estimation result from the channel measuring unit 1059. Thecontrol unit 103 outputs a signal to be coded to the coding unit 1071.Furthermore, the control unit 103 is used to control the entirety or apart of the base station device 1.

The upper layer processing unit 101 performs processing and managementregarding RAT control, radio resource control, a subframe setting,scheduling control, and/or channel state information (CSI) reportcontrol. The processing and the management in the upper layer processingunit 101 are performed for every terminal device or in common betweenterminal devices connected to the base station device. The processingand the management in the upper layer processing unit 101 may beperformed only by the upper layer processing unit 101 or may be acquiredfrom an upper node or another base station device. Furthermore, theprocessing and the management in the upper layer processing unit 101 maybe individually performed according to the RAT. For example, the upperlayer processing unit 101 individually performs processing andmanagement in the LTE and processing and management in the NR.

In the RAT control in the upper layer processing unit 101, managementregarding the RAT is performed. For example, in the RAT control,management regarding the LTE and/or management regarding the NR isperformed. The management regarding the NR includes a setting andprocessing of a parameter set regarding a transmission signal in the NRcell.

In the radio resource control in the upper layer processing unit 101,generation and/or management of downlink data (transport block), systeminformation, an RRC message (RRC parameter), and/or an MAC controlelement (CE) is performed.

In the subframe setting in the upper layer processing unit 101,management of a subframe setting, a subframe pattern setting, anuplink-downlink setting, an uplink reference UL-DL setting, and/or adownlink reference UL-DL setting is performed. Note that the subframesetting in the upper layer processing unit 101 is also referred to as abase station subframe setting. Furthermore, the subframe setting in theupper layer processing unit 101 can be determined on the basis of atraffic volume of an uplink and a traffic volume of a downlink.Furthermore, the subframe setting in the upper layer processing unit 101can be determined on the basis of a scheduling result of the schedulingcontrol in the upper layer processing unit 101.

In the scheduling control in the upper layer processing unit 101, afrequency and a subframe to which a physical channel is allocated, acoding rate and a modulation manner of the physical channel, atransmission power, and the like, are determined on the basis ofreceived channel state information and an estimated value of apropagation path, a quality of a channel or the like input from channelmeasuring unit 1059. For example, the control unit 103 generates controlinformation (downlink control information (DCI) format) on the basis ofthe scheduling result of the scheduling control in the upper layerprocessing unit 101.

In the CSI report control in the upper layer processing unit 101, a CSIreport of the terminal device 2 is controlled. For example, a settingregarding a CSI reference resource to be assumed in order to calculateCSI in the terminal device 2 is controlled.

The reception unit 105 receives a signal transmitted from the terminaldevice 2 via the transmission/reception antenna 109 according to thecontrol from the control unit 103, further performs reception processingsuch as demultiplexing, demodulation, decoding, and the like, andoutputs information subjected to the reception processing to controlunit 103. Note that the reception processing in the reception unit 105is performed on the basis of a predefined setting or a setting of whichthe base station device 1 notifies the terminal device 2.

The wireless receiving unit 1057 performs conversion to an intermediatefrequency (down-conversion), removal of an unnecessary frequencycomponent, control of an amplification level so that a signal level isappropriately maintained, orthogonal demodulation based on in-phase andorthogonal components of the received signal, conversion from an analogsignal to a digital signal, removal of a guard interval (GI), and/orextraction of a frequency domain signal by fast Fourier transform (FFT)on an uplink signal received via the transmission/reception antenna 109.

The demultiplexing unit 1055 demultiplexes an uplink channel such as aphysical uplink control channel (PUCCH), a physical uplink sharedchannel (PUSCH) or the like and/or an uplink reference signal from thesignal input from the wireless receiving unit 1057. The demultiplexingunit 1055 outputs the uplink reference signal to the channel measuringunit 1059. The demultiplexing unit 1055 performs compensation of thepropagation path for the uplink channel from the estimated value of thepropagation path input from the channel measuring unit 1059.

The demodulating unit 1053 performs demodulation of the received signalusing a modulation manner such as binary phase shift keying (BPSK),quadrature phase shift keying (QPSK), 16-quadrature amplitude modulation(16QAM), 64QAM, 256QAM, or the like, for a modulation symbol of theuplink channel. The demodulating unit 1053 performs demultiplexing andmodulation of a multiple-input multiple-output (MIMO)-multiplexed uplinkchannel.

The decoding unit 1051 performs decoding processing on coded bits of thedemodulated uplink channel. The decoded uplink data and/or uplinkcontrol information is output to the control unit 103. The decoding unit1051 performs decoding processing on the PUSCH for every transportblock.

The channel measuring unit 1059 measures the estimated value of thepropagation path, the quality of the channel or the like from the uplinkreference signal input from the demultiplexing unit 1055, and outputsthe estimated value of the propagation path, the quality of the channelor the like to the demultiplexing unit 1055 and/or the control unit 103.For example, the channel measuring unit 1059 measures the estimatedvalue of the propagation path for performing compensation of thepropagation path for the PUCCH or the PUSCH using an uplink demodulationreference signal (UL-DMRS), and measures the quality of the channel inthe uplink using a sounding reference signal (SRS).

The transmission unit 107 performs transmission processing such ascoding, modulation, multiplexing, and the like, on downlink controlinformation and downlink data input from the upper layer processing unit101 according to the control from the control unit 103. For example, thetransmission unit 107 generates and multiplexes a physical hybridautomatic repeat request (HARQ) indicator channel (PHICH), a physicaldownlink control channel (PDCCH), an enhanced PDCCH (EPDCCH), a physicaldownlink shared channel (PDSCH), and a downlink reference signal togenerate a transmission signal. Note that the transmission processing inthe transmission unit 107 is performed on the basis of a predefinedsetting, a setting of which the base station device 1 notifies theterminal device 2, or a setting notification of which is providedthrough the PDCCH or the EPDCCH transmitted in the same subframe.

The coding unit 1071 performs coding using a predetermined coding mannersuch as block coding, convolutional coding, turbo coding, or the like,on an HARQ indicator (HARQ-ACK), the downlink control information, andthe downlink data input from the control unit 103. The modulating unit1073 modulates coded bits input from the coding unit 1071 in apredetermined modulation manner such as BPSK, QPSK, 16QAM, 64QAM,256QAM, or the like. The downlink reference signal generating unit 1079generates a downlink reference signal on the basis of a physical cellidentifier (PCI), an RRC parameter set in the terminal device 2, and thelike. The multiplexing unit 1075 multiplexes a modulation symbol of eachchannel and the downlink reference signal and arranges the multiplexedmodulation symbol and downlink reference signal in a predeterminedresource element.

The wireless transmitting unit 1077 performs processing such asconversion into a time domain signal by inverse fast Fourier transform(IFFT), addition of a guard interval, generation of a baseband digitalsignal, conversion to an analog signal, orthogonal modulation,conversion (up convert) from an intermediate frequency signal to a highfrequency signal, removal of an extra frequency component, amplificationof power, and the like, on the signal from the multiplexing unit 1075 togenerate a transmission signal. The transmission signal output by thewireless transmitting unit 1077 is transmitted from thetransmission/reception antenna 109.

<Configuration Example of Terminal Device in Present Embodiment>

FIG. 3 is a schematic block diagram illustrating a configuration of theterminal device 2 according to the present embodiment. As illustrated inFIG. 3, the terminal device 2 includes an upper layer processing unit201, a control unit 203, a reception unit 205, a transmission unit 207,and a transmission/reception antenna 209. Furthermore, the receptionunit 205 includes a decoding unit 2051, a demodulating unit 2053, ademultiplexing unit 2055, a wireless receiving unit 2057, and a channelmeasuring unit 2059. Furthermore, the transmission unit 207 includes acoding unit 2071, a modulating unit 2073, a multiplexing unit 2075, awireless transmitting unit 2077, and an uplink reference signalgenerating unit 2079.

As described above, the terminal device 2 can support one or more RATS.Some or all of respective units included in the terminal device 2illustrated in FIG. 3 may be individually configured according to theRAT. For example, the reception unit 205 and the transmission unit 207are individually configured in LTE and NR. Furthermore, in an NR cell,some or all of the respective units included in the terminal device 2illustrated in FIG. 3 may be individually configured according to aparameter set regarding a transmission signal. For example, in the NRcell, the wireless receiving unit 2057 and the wireless transmittingunit 2077 may be individually configured according to the parameter setregarding the transmission signal.

The upper layer processing unit 201 outputs uplink data (transportblock) to the control unit 203. The upper layer processing unit 201performs processing of a medium access control (MAC) layer, a packetdata convergence protocol (PDCP) layer, a radio link control (RLC)layer, and a radio resource control (RRC) layer. Furthermore, the upperlayer processing unit 201 generates control information for controllingthe reception unit 205 and the transmission unit 207, and outputs thecontrol information to the control unit 203.

The control unit 203 controls the reception unit 205 and thetransmission unit 207 on the basis of the control information from theupper layer processing unit 201. The control unit 203 generates controlinformation for the upper layer processing unit 201 and outputs thecontrol information to the upper layer processing unit 201. The controlunit 203 inputs a decoded signal from the decoding unit 2051 and achannel estimation result from the channel measuring unit 2059. Thecontrol unit 203 outputs a signal to be coded to the coding unit 2071.Furthermore, the control unit 203 may be used to control the entirety ora part of the terminal device 2.

The upper layer processing unit 201 performs processing and managementregarding RAT control, radio resource control, a subframe setting,scheduling control, and/or channel state information (CSI) reportcontrol. The processing and the management in the upper layer processingunit 201 are performed on the basis of a predefined setting and/or asetting based on control information set or provided in notificationfrom the base station device 1. For example, the control informationfrom the base station device 1 includes an RRC parameter, an MAC controlelement, or DCI. Furthermore, the processing and the management in theupper layer processing unit 201 may be individually performed accordingto the RAT. For example, the upper layer processing unit 201individually performs processing and management in the LTE andprocessing and management in the NR.

In the RAT control in the upper layer processing unit 201, managementregarding the RAT is performed. For example, in the RAT control,management regarding the LTE and/or management regarding the NR isperformed. The management regarding the NR includes a setting andprocessing of a parameter set regarding a transmission signal in the NRcell.

In the radio resource control in the upper layer processing unit 201,management of setting information of the terminal device is performed.In the radio resource control in the upper layer processing unit 201,generation and/or management of uplink data (transport block), systeminformation, an RRC message (RRC parameter), and/or an MAC controlelement (CE) is performed.

In the subframe setting in the upper layer processing unit 201, asubframe setting in the base station device 1 and/or a base stationdevice different from the base station device 1 is managed. The subframesetting includes an uplink or downlink setting for a subframe, asubframe pattern setting, an uplink-downlink setting, an uplinkreference UL-DL setting, and/or a downlink reference UL-DL setting. Notethat the subframe setting in the upper layer processing unit 201 is alsoreferred to as a terminal subframe setting.

In the scheduling control in the upper layer processing unit 201,control information for controlling scheduling for the reception unit205 and the transmission unit 207 is generated on the basis of DCI(scheduling information) from the base station device 1.

In the CSI report control in the upper layer processing unit 201,control regarding a report of CSI to the base station device 1 isperformed. For example, in the CSI report control, a setting regarding aCSI reference resource to be assumed in order to calculate CSI in thechannel measuring unit 2059 is controlled. In the CSI report control, aresource (timing) used to report the CSI is controlled on the basis ofthe DCI and/or the RRC parameter.

The reception unit 205 receives a signal transmitted from the basestation device 1 via the transmission/reception antenna 209 according tothe control from the control unit 203, further performs receptionprocessing such as demultiplexing, demodulation, decoding, and the like,and outputs information subjected to the reception processing to controlunit 203. Note that the reception processing in the reception unit 205is performed on the basis of a predefined setting or a notification or asetting from the base station device 1.

The wireless receiving unit 2057 performs conversion to an intermediatefrequency (down-conversion), removal of an unnecessary frequencycomponent, control of an amplification level so that a signal level isappropriately maintained, orthogonal demodulation based on in-phase andorthogonal components of the received signal, conversion from an analogsignal to a digital signal, removal of a guard interval (GI), and/orextraction of a frequency domain signal by fast Fourier transform (FFT)on an uplink signal received via the transmission/reception antenna 209.

The demultiplexing unit 2055 demultiplexes a downlink channel such as aPHICH, a PDCCH, an EPDCCH, a PDSCH, or the like, a downlinksynchronization signal, and/or a downlink reference signal from thesignal input from the wireless receiving unit 2057. The demultiplexingunit 2055 outputs the downlink reference signal to the channel measuringunit 2059. The demultiplexing unit 2055 performs compensation of apropagation path for the downlink channel from an estimated value of apropagation path input from the channel measuring unit 2059.

The demodulating unit 2053 performs demodulation of the received signalusing a modulation manner such as BPSK, QPSK, 16QAM, 64QAM, 256QAM, orthe like, for a modulation symbol of the downlink channel. Thedemodulating unit 2053 performs demultiplexing and modulation of amultiple-input multiple-output (MIMO)-multiplexed downlink channel.

The decoding unit 2051 performs decoding processing on coded bits of thedemodulated downlink channel. The decoded downlink data and/or downlinkcontrol information is output to the control unit 203. The decoding unit2051 performs decoding processing on the PDSCH for every transportblock.

The channel measuring unit 2059 measures the estimated value of thepropagation path, a quality of a channel or the like from the downlinkreference signal input from the demultiplexing unit 2055, and outputsthe estimated value of the propagation path, the quality of the channelor the like to the demultiplexing unit 2055 and/or the control unit 203.The downlink reference signal that the channel measuring unit 2059 usesfor measurement may be determined at least on the basis of atransmission mode set by the RRC parameter and/or other RRC parameters.For example, a DL-DMRS measures an estimated value of a propagation pathfor performing propagation path compensation for the PDSCH or theEPDCCH. A CRS measures an estimated value of the propagation path forperforming propagation path compensation for the PDCCH or the PDSCHand/or a channel on the downlink for reporting the CSI. A CSI-RSmeasures the channel in the downlink for reporting the CSI. The channelmeasuring unit 2059 calculates a reference signal received power (RSRP)and/or a reference signal received quality (RSRQ) on the basis of theCRS, the CSI-RS, or a detection signal, and outputs the RSRP and theRSRQ to the upper layer processing unit 201.

The transmission unit 207 performs transmission processing such ascoding, modulation, multiplexing, and the like, on uplink controlinformation and uplink data input from the upper layer processing unit201 according to the control from the control unit 203. For example, thetransmission unit 207 generates and multiplexes an uplink channel suchas a PUSCH, a PUCCH or the like, and/or an uplink reference signal togenerate a transmission signal. Note that the transmission processing inthe transmission unit 207 is performed on the basis of a predefinedsetting or a setting or a notification from the base station device 1.

The coding unit 2071 performs coding using a predetermined coding mannersuch as block coding, convolutional coding, turbo coding, or the like,on an HARQ indicator (HARQ-ACK), the uplink control information, and theuplink data input from the control unit 203. The modulating unit 2073modulates coded bits input from the coding unit 2071 in a predeterminedmodulation manner such as BPSK, QPSK, 16QAM, 64QAM, 256QAM, or the like.The uplink reference signal generating unit 2079 generates an uplinkreference signal on the basis of the RRC parameter and the like set inthe terminal device 2. The multiplexing unit 2075 multiplexes amodulation symbol of each channel and the uplink reference signal andarranges the multiplexed modulation symbol and uplink reference signalin a predetermined resource element.

The wireless transmitting unit 2077 performs processing such asconversion into a time domain signal by inverse fast Fourier transform(IFFT), addition of a guard interval, generation of a baseband digitalsignal, conversion to an analog signal, orthogonal modulation,conversion (up convert) from an intermediate frequency signal to a highfrequency signal, removal of an extra frequency component, amplificationof power, and the like, on the signal from the multiplexing unit 2075 togenerate a transmission signal. The transmission signal output by thewireless transmitting unit 2077 is transmitted from thetransmission/reception antenna 209.

<Details of Sidelink of LTE in Present Embodiment>

In LTE, sidelink communication is performed. The sidelink communicationis direct communication between a terminal device and a terminal devicedifferent from the terminal device. In a sidelink, candidates for timeand frequency resources used for transmission and reception of thesidelink, called a resource pool are set in the terminal device,resources for transmission and reception of the sidelink are selectedfrom the resource pool, and the sidelink communication is performed.Since the sidelink communication is performed using an uplink resource(uplink subframe or uplink component carrier), the resource pool is alsoset to the uplink subframe or the uplink component carrier.

A sidelink physical channel includes a physical sidelink control channel(PSCCH), a physical sidelink shared channel (PSSCH), a sidelinkacknowledgement (ACK)/negative ACK (NACK) channel, and the like.

The PSCCH is used to transmit sidelink control information (SCI).Mapping of information bits of the sidelink control information isdefined as an SCI format. The sidelink control information includes asidelink grant. The sidelink grant is used for scheduling of the PSSCH.

The PSSCH is used to transmit sidelink data (sidelink shared channel(SLL-SCH)). Note that the PSSCH may also be used to transmit controlinformation of an upper layer.

The sidelink ACK/NACK channel is used to answer an ACK/NACK to adecoding result of the PSSCH to a transmission terminal device.

The resource pool is set from the base station device to the terminaldevice by a system information block (SIB) or a dedicated RRC message.Alternatively, the resource pool is set by information regarding theresource pool preset in the terminal device. A time resource pool isindicated by cycle information, offset information, and subframe bitmapinformation. A frequency resource pool is indicated by a start positionof a resource block, an end position of the resource block, and thenumber of consecutive resource blocks.

<Details of Sidelink of NR in Present Embodiment>

Hereinafter, details of allocation of a resource pool of a sidelink inNR will be described.

In sidelink communication in a cell coverage, the resource pool of thesidelink in the NR can be dynamically set. The resource pool of thesidelink in the NR is indicated from a base station by an NR-PDCCH. Thatis, NR-DCI included in the NR-PDCCH indicates a resource block and asubframe in which an NR-PSCCH, an NR-PSSCH, and a sidelink ACK/NACKchannel are transmitted and received.

FIG. 4 is a diagram illustrating an example of dynamic resource poolallocation of a sidelink. The first terminal device sets three subframesincluding and following a subframe in which an NR-PDCCH is transmitted,as a resource pool for sidelink communication, by the NR-PDCCH. Thefirst terminal device waits for a gap time for reception/transmissionswitching and generation processing of an NR-PSCCH and an NR-PSSCH, andthen transmits the NR-PSCCH to the second terminal device using theresource pool designated by the NR-PDCCH. Moreover, the first terminaldevice transmits an NR-PSSCH scheduled according to an NR-SCI formatincluded in the NR-PSCCH to the second terminal device using theresource pool designated in the NR-PDCCH. Finally, the second terminaldevice waits for a gap time for generation processing of a sidelinkACK/NACK channel, and then transmits information of an ACK/NACK responseto the NR-PSSCH transmitted from the first terminal device to the firstterminal device on the sidelink ACK/NACK channel, using the resourcepool designated by the NR-PDCCH.

As an example of indication of a time resource pool by the NR-PDCCH, atime resource used for the sidelink communication is indicated as aresource pool of a sidelink from the NR-PDCCH to a predeterminedsubframe in a case where DCI indicating the sidelink communication hasbeen included in the NR-PDCCH. The first terminal device recognizes thetime resource pool from a subframe in which the DCI indicating thesidelink communication has been received. A predetermined subframe maybe preset to, for example, three subframes or the like or may be setfrom an upper layer such as an SIB, a dedicated RRC message or the like.

As an example of indication of a time resource pool by the NR-PDCCH,information indicating a subframe is included in DCI included in theNR-PDCCH and indicating the sidelink communication, and a resource poolof a time resource used for the sidelink communication is indicated onthe basis of the information. The first terminal device recognizes thetime resource pool from the information indicating the subframe. As amethod of indicating the subframe, for example, there are a subframenumber, the number of subframes from the NR-PDCCH to the time resourcepool, and the like.

As an example of indication of a frequency resource by the NR-PDCCH, afrequency resource used for the sidelink communication is indicated onthe basis of resource allocation information, which is one of parametersof the DCI included in the NR-PDCCH and indicating the sidelinkcommunication. The first terminal device recognizes that a resourceblock indicated by the resource allocation information is a resourcepool. The resource allocation information is information indicating atleast a resource in which the NR-PSCCH is transmitted.

Note that notification of the resource allocation information may beindividually provided by information indicating a resource in which theNR-PSCCH is transmitted, information indicating a resource in which theNR-PSSCH is transmitted, and information indicating a resource in whichthe sidelink ACK/NACK channel is transmitted.

Note that the resource in which the NR-PSSCH is transmitted and theresource in which the sidelink ACK/NACK channel is transmitted may belinked to the information indicating the resource in which the NR-PSCCHis transmitted. For example, a frequency resource in which the NR-PSSCHis transmitted may be the same as a frequency resource in which theNR-PSCCH is transmitted. For example, the resource in which the sidelinkACK/NACK channel is transmitted and the frequency resource in which theNR-PSSCH is transmitted may be the same as the frequency resource inwhich the NR-PSCCH is transmitted.

Note that resource pools of a plurality of NR component carriers may beindicated by one NR-PDCCH. For example, a resource pool used forsidelink communication between a primary cell and a secondary cell ofthe NR may be set from an NR-PDCCH transmitted in the primary cell ofthe NR.

Note that a subframe and a resource block in which the resource pool canbe indicated by the NR-PDCCH may be limited by upper layer information.The upper layer information is, for example, terminal-unique settinginformation such as a dedicated RRC message or the like or notificationinformation such as an SIB or the like. Candidates for time andfrequency resource pools are set by the upper layer information, and asubframe and a resource block that can actually be used as the resourcepool are indicated from the candidates by the DCI included in theNR-PDCCH and indicating the sidelink communication.

It is preferable that the NR-PDCCH including information regarding theresource pool of the sidelink is transmitted uniquely to a terminaldevice or uniquely to a terminal device group. That is, it is preferablethat the NR-PDCCH including resource pool information of the sidelink isarranged in a search space determined by terminal device-uniqueinformation such as a cell radio network temporary identify (C-RNTI) orthe like or is arranged in a search space determined by terminal devicegroup-unique information.

As an example of monitoring of the NR-PSCCH of the second terminaldevice, the second terminal device always monitors both the NR-PDCCH andthe NR-PSCCH. The second terminal device shifts to uplink transmissionprocessing, downlink reception processing, or NR-PSCCH transmissionprocessing in a case where the second terminal device has detected anNR-PDCCH addressed to the second terminal device, and attemptsmonitoring of the NR-PSCCH otherwise. In this case, for the secondterminal device, a plurality of resource candidates (NR-PSCCHcandidates) in which there is a possibility that the NR-PSCCH will betransmitted is set from an upper layer or is preset. The second terminaldevice attempts blind decoding of the NR-PSCCH in the set NR-PSCCHcandidates. Notification of setting information of the NR-PSCCHcandidate is provided to the second terminal device by a dedicated RRCmessage in a case where the second terminal device is in an RRCconnection state with the base station device, and is provided to thesecond terminal device by a sidelink notice channel (NR-PSBCH) of the NRtransmitted by the first terminal device in a case where the secondterminal device is not in the RRC connection state with the base stationdevice. Setting information included in the NR-PSBCH is information setfrom the base station device in a case where the first terminal deviceexists inside the cell, and is preset information in a case where thefirst terminal device exists outside the cell.

Note that the resource pool in which the NR-PSBCH is transmitted mayalso be indicated by the NR-PDCCH. A method of indicating the resourcepool in which the NR-PSBCH is transmitted may be similar to a method ofindicating the resource pool in which the NR-PSCCH is transmitted.

As another example of monitoring of the NR-PSCCH of the second terminaldevice, in a case where the second terminal device is inside the cell,the second terminal device can receive an NR-PDCCH in which the resourcepool is designated. The second terminal device attempts decoding of theNR-PSCCH in the resource in which the NR-PSCCH is transmitted, on thebasis of information of the resource pool included in the NR-PDCCH in acase where the second terminal device has received the NR-PDCCH, andwaits for processing of monitoring until the next unit frame otherwise.Therefore, an operation of attempting the decoding of the NR-PSCCHplural times in one unit frame may not be performed, and an effect suchas low power consumption, simplification of a receiver, or the like, ofthe terminal device can thus be expected.

FIG. 5 is a diagram illustrating an example of dynamic resource poolallocation of a sidelink. As a difference from FIG. 4, in a case whereself-completion type transmission is possible even in sidelinkcommunication, transmission and reception of an NR-PSCCH, an NR-PSSCH,and a sidelink ACK/NACK channels can be completed in a resource pool forsidelink transmission allocated within one predetermined transmissionand reception time (for example, a unit frame time), as illustrated inFIG. 5. The first terminal device recognizes the resource pool of thesidelink on the basis of DCI (DCI for a first sidelink) included in theNR-PDCCH and indicating the sidelink communication after receiving theNR-PDCCH. Then, the first terminal device transmits the NR-PSCCH and theNR-PSSCH using the resource pool of the sidelink indicated from the DCIfor a first sidelink. The second terminal device attempts decoding ofthe NR-PSSCH on the basis of information included in the NR-PSCCH afterreceiving the NR-PSCCH transmitted from the first terminal device.

The first terminal device can determine a channel length of the NR-PSSCHon the basis of information regarding a time resource of the sidelinkincluded in the DCI for a first sidelink. Alternatively, the firstterminal device can recognize a time resource of the sidelink includedin the NR-PDCCH on the basis of information regarding a channel lengthof the NR-PSSCH included in the DCI for a first sidelink.

Therefore, the self-completion type transmission becomes possible evenin the sidelink communication, and by performing flexible resourcecontrol, resource utilization efficiency of a system becomes good.

FIG. 6 is a diagram illustrating an example of dynamic resource poolallocation of a sidelink. As a difference from FIG. 5, the firstterminal device indicates scheduling information of NR-PSSCHtransmission from the second terminal device for the second terminaldevice using an NR-PSCCH. The second terminal waits for a gap time forreception processing of the NR-PSCCH and transmission processing of anNR-PSSCH, and then transmits the NR-PSSCH on the basis of informationindicated from the NR-PSSCH. Therefore, in particular, even in a casewhere the second terminal device exists outside the cell, the basestation device can dynamically control the resource for sidelinkcommunication used by the second terminal device via the first terminaldevice, such that resource utilization efficiency of the system becomesgood.

DCI (DCI for a second sidelink) included in the NR-PSCCH transmitted inFIG. 6 and indicating sidelink communication is different from the DCIfor a first sidelink included in the NR-PSCCH transmitted in FIG. 5 andindicating the sidelink communication. The DCI included in the NR-PSCCHtransmitted in FIG. 5 and indicating the sidelink communication is DCIfor scheduling resources for the first terminal device to transmit theNR-PSCCH and the NR-PSSCH to the second terminal device, and the DCIincluded in the NR-PSCCH transmitted in FIG. 6 and indicating thesidelink communication is DCI for scheduling a resource for the firstterminal device to transmit the NR-PSCCH to the second terminal deviceand a resource for the second terminal device to transmit the NR-PSSCHscheduled by the NR-PSCCH to the first terminal device.

Furthermore, SCI (first SCI) included in the NR-PSCCH transmitted inFIG. 5 and SCI (second SCI) included in the NR-PSCCH transmitted in FIG.6 are different from each other. The first SCI is used to instruct thesecond terminal device to receive the NR-PSSCH transmitted from thefirst terminal device, and the second SCI is used to instruct the secondterminal device to transmit the NR-PSSCH to the first terminal device.

FIG. 7 is a diagram illustrating an example of dynamic resource poolallocation of a sidelink. In FIG. 7, terminal device relay is assumed.In FIG. 7, further from FIG. 6, scheduling of an NR-PUSCH in addition toindication of the resource pool of a sidelink is performed by anNR-PDCCH. Similar to FIG. 6, the first terminal device instructs thesecond terminal device to transmit an NR-PSSCH by an NR-PSCCH, andreceives an SL-SCH from the second terminal device. Then, the firstterminal device includes the received SL-SCH in the NR-PUSCH andtransmits the NR-PUSCH to the base station device. Therefore, a resourcepool of the sidelink and the NR-PUSCH can be scheduled by one NR-PDCCH,and it is thus possible to realize low-delay terminal device relay whilereducing an overhead due to the NR-PDCCH.

FIG. 8 is a diagram illustrating an example of dynamic resource poolallocation of a sidelink. In FIG. 8, a resource pool of a sidelink isindicated on a radio frame basis by an NR-PDCCH. Transmission isperformed in subframe #0.

Resource pool information of the sidelink included in the NR-PDCCH isindicated by bitmap information in which a subframe in which theresource pool of the sidelink is set is indicated by 1 or 0, a startposition S1 of a resource block, an end position S2 of the resourceblock, and the number M of consecutive resource blocks.

It is preferable that the NR-PDCCH including the resource poolinformation of the sidelink is sent to a terminal share. That is, it ispreferable that the NR-PDCCH including the resource pool information ofthe sidelink is arranged in a search space common between terminaldevices.

In a case where the terminal device has received the NR-PDCCH includingthe resource pool information of the sidelink in subframe #0, theresource pool is set using the resource pool information between theradio frames that have received the NR-PDCCH. On the other hand, in acase where the terminal device has received the NR-PDCCH including theresource pool information of the sidelink in subframe #0, it is assumedthat the resource pool is not set between the radio frames.

2. Technical Problem

Next, a technical problem of the communication system according to theembodiment of the present disclosure will be described with particularattention to a case where V2X (particularly V2V) is realized usingsidelink communication of NR.

As described above, in the NR, in addition to support of a V2X use caseof the LTE, it has been required to support use cases with higherrequirements, such as vehicles platooning, extended sensors, advanceddriving, remote driving, or the like. In order to support these usecases, a higher throughput, lower latency, and higher reliability havebeen required, such that an operation in a millimeter wave such as a 60GHz band or the like has also been studied. Meanwhile, the millimeterwave has significant radio wave attenuation, such that communicationusing the millimeter wave may require a technology called beamforming.

Furthermore, in device-to-device (D2D), synchronization signals (primarysidelink synchronization signal (PSSS)/secondary sidelinksynchronization signal (SSSS) and PSBCH) are broadcast from apredetermined terminal as a synchronization method of communicationbetween terminals outside a coverage. For example, FIG. 9 is anexplanatory diagram for describing an outline of D2D, and illustrates anexample of a synchronization method of communication between terminalsoutside a coverage. In the example illustrated in FIG. 9, a terminaldevice 2 a located in the coverage broadcasts synchronization signals(PSSS/SSSS) to other terminal devices 2 b and 2 c located in thevicinity of the terminal device 2 a. Therefore, for example, even thoughthe terminal devices 2 b and 2 c are located outside the coverage, theterminal devices 2 b and 2 c can recognize links of the D2Dcommunication by receiving the synchronization signals broadcast fromthe terminal device 2 a. That is, even in a situation where some of theterminal devices 2 are located outside the coverage, an operation of theD2D including some of the terminal devices 2 by the configuration asdescribed above becomes possible.

Moreover, as described above, in the V2V communication of the NR, a highthroughput is required, such that introduction of unicast communicationis expected. Advantages of the unicast communication over broadcastcommunication are as follows:

Retransmission processing such as HARQ is easy.

Processing of closed loop control (link adaptation, transmission powercontrol, beam adaptation, and the like) can be applied.

Meanwhile, as described above, in the NR, by forming a beam withimproved directivity by narrowing a radio signal by the beamforming, itbecomes possible to communicate with a terminal device located fartheraway even in a case where the millimeter wave having the significantradio wave attenuation was used. Meanwhile, under such a situation, whenstarting the V2V communication, adjustment of a transmission beam and areception beam as well as synchronization is required between theterminal devices.

For example, FIG. 10 is an explanatory diagram for describing an outlineof the V2V communication of the NR, and illustrates an example of asituation in which adjustment of a transmission beam and a receptionbeam is required. For example, in the example illustrated in FIG. 10, aterminal device 2 a located in a coverage broadcasts a synchronizationsignal (PSSS/SSSS) to another terminal device 2 b located in thevicinity of the terminal device 2 a. At this time, in the V2Vcommunication of the NR, a transmission beam formed by the terminaldevice 2 a and a reception beam formed by the terminal device 2 b needto be appropriately determined according to a positional relationshipbetween the terminal device 2 a and the terminal device 2 b. In aconventional beam connection setup between a downlink and an uplink, abeam of the downlink is first aligned, and a beam of the uplinkcorresponding to the downlink is then selected. However, in sidelinkcommunication applied to the V2V communication, a concept of the uplinkand the downlink does not exist. Therefore, it becomes necessary todefine which vehicle (terminal device) performs a beam connection towhich vehicle (terminal device).

Furthermore, in the V2V communication of the NR, there may be arestriction called a so-called half duplex (HD) that transmission andreception are limited to be performed in a time division manner, suchthat the transmission or the reception cannot be always performed. Byapplying such an HD restriction, for example, it becomes difficult for avehicle (terminal device) that is performing the transmission to performthe reception at the same time. That is, due to the HD limitation, itbecomes difficult for a vehicle that is transmitting a signal for beamconnection to receive a signal from another vehicle.

For example, FIG. 11 is an explanatory diagram for describing an outlineof the HD limitation. In an example illustrated in FIG. 11, a terminaldevice 2 a (vehicle) is transmitting a signal (for example, PSSS/SSSS)to a terminal device 2 b (vehicle). At this timing, even though a signal(for example, PSSS/SSSS) was being transmitted from a terminal device 2c located in the vicinity of the terminal device 2 a, it becomesdifficult for the terminal device 2 a to receive the signal transmittedfrom the terminal device 2 c due to the HD limitation.

Furthermore, in a case where unicast communication is applied, it isnecessary to consider synchronization for establishing the unicastcommunication. Specifically, in the unicast communication, improve ofresource efficiency can be expected by performing resource allocation toa plurality of terminal devices by frequency division multiplexing (FDM)or space division multiplexing (SDM). On the other hand, in order torealize the resource allocation by the FDM or the SDM, it can benecessary to align timing between a transmission symbol and a receptionsymbol between the terminal devices.

In view of the circumstance as described above, the present disclosureproposes a technology capable of realizing establishment of inter-devicecommunication (for example, V2X communication typified by V2V) betweenterminal devices in which application of NR is assumed, in a moresuitable manner. Specifically, the present disclosure proposes atechnology capable of more rapidly establishing inter-devicecommunication between terminal devices with beam connection under an HDrestriction.

3. Technical Feature

Hereinafter, a technical feature of the system according to theembodiment of the present disclosure will be described.

In the system according to the embodiment of the present disclosure, aplurality of sidelink synchronization signal (SLSS) blocks istransmitted. The SLSS block includes, for example, primary sidelinksynchronization signal (PSSS)/secondary sidelink synchronization signal(SSSS)/PSBCH, synchronization signal+broadcast information, and thelike. One SLSS is transmitted using a predetermined transmission beam. Adifferent transmission beam is applied to each SLSS block. In otherwords, the SLSS blocks (in other words, synchronization signals) areassociated with each of a plurality of beams allocated to be availablefor inter-device communication between a plurality of terminal devices 2different from each other. An index is associated with each SLSS block.It becomes possible to identify the transmission beam by the indexassociated with the SLSS block. For example, FIG. 12 is an explanatorydiagram for describing an example of a configuration of an SLSS block.In the example illustrated in FIG. 12, a PSSS, an SSSS, and a PSBCH areallocated to regions (for example, regions in a time direction and afrequency direction) to which resources of wireless communication areallocated. Of course, the example illustrated in FIG. 12 is mere anexample, and the regions to which resources are allocated may beappropriately changed according to a communication manner of wirelesscommunication.

The plurality of SLSS blocks described above is transmitted from theterminal device 2 to another terminal device 2. As a specific example,the terminal device 2 a transmits the plurality of SLSS blocks. Anotherterminal device 2 b performs synchronization and beam adjustment betweenanother terminal device 2 b and the terminal device 2 a using an SLSSblock having the highest reference signal received power (RSRP) amongthe SLSS blocks received from the terminal device 2 a.

<Arrangement Example of SLSS Blocks>

Here, an example of arranging the SLSS blocks with respect to theregions to which the resources of the wireless communication areallocated will be described with reference to FIGS. 13 to 17. Forexample, FIG. 13 is an explanatory diagram for describing an outline ofan example of an arrangement of the SLSS blocks, and illustrates anexample of beams associated with the SLSS blocks. That is, in thepresent description, for convenience, it is assumed that the terminaldevice 2 forms four beams (that is, beams #0 to #3) in differentdirections, as illustrated in FIG. 13. Note that the number of beamsthat the terminal device of the present embodiment has is not limited tofour, and the present disclosure can be similarly applied to all of aplurality of beams.

Arrangement Pattern 1 (Localized Manner) of SLSS Blocks

Next, an example of an arrangement pattern of the SLSS blocks will bedescribed. For example, FIG. 14 is an explanatory diagram for describingan example of an arrangement pattern of the SLSS blocks. Specifically,FIG. 14 illustrates an example of a pattern related to an arrangement ofthe SLSS blocks in a case where the SLSS blocks are arranged in a timedirection. In FIG. 14, a horizontal axis represents a time.

In the example illustrated in FIG. 14, an arrangement of SLSS blocks forevery terminal device 2 is patterned so that the SLSS blocks for everyterminal device 2 are continuously transmitted in a predeterminedsection (for example, in a slot, in a half frame, or in a radio frame).With such a configuration, in the example illustrated in FIG. 14, itbecomes possible to shorten a search time of the SLSS blocks for everyterminal device 2.

Arrangement Pattern 2 (Distributed Manner) of SLSS Blocks

Furthermore, FIG. 15 is an explanatory diagram for describing anotherexample of an arrangement pattern of the SLSS blocks. Specifically, FIG.15 illustrates another example of a pattern related to an arrangement ofthe SLSS blocks in a case where the SLSS blocks are arranged in a timedirection. In FIG. 15, a horizontal axis represents a time.

In the example illustrated in FIG. 15, an arrangement of SLSS blocks forevery terminal device 2 is patterned so that the SLSS blocks for everyterminal device 2 are transmitted in a distributed manner. With such aconfiguration, in the example illustrated in FIG. 15, it becomespossible to use regions (for example, periods in the time direction) inwhich the SLSS blocks for every terminal device 2 are not transmitted,for transmission of other data (for example, ultra-reliable and lowlatency communications (URLLC) data, emergency data, and the like).

<Candidate for Arrangement Pattern of SLSS Blocks>

Next, an example of a case where candidates for an arrangement patternof the SLSS blocks is set in advance and the terminal device 2 selects acandidate to be used as an arrangement pattern of the SLSS blocks by theterminal device 2 among the candidates will be described. Note that inthe following description, each of the candidates for the arrangementpattern of the SLSS blocks is also referred to as an “SLSS block set”for convenience. Furthermore, the SLSS block set corresponds to anexample of a “synchronization signal set” in which a plurality ofsynchronization signals (for example, a plurality of SLSS blocks) isassociated with each other.

Setting Example 1 (Localized Manner) of SLSS Block Set

For example, FIG. 16 is an explanatory diagram for describing an exampleof a setting method of the SLSS block set. Specifically, FIG. 16illustrates an example of a setting method of the SLSS block set in acase where the SLSS blocks are arranged in the time direction. In FIG.16, a horizontal axis represents a time. Furthermore, FIG. 16illustrates an example of a case where SLSS block sets #0 to #4 are set.Specifically, in the example illustrated in FIG. 16, for each of theSLSS block sets #0 to #3, each SLSS block set is set so that a series ofSLSS blocks are continuously transmitted in a predetermined section (forexample, in a slot, in a half frame, or in a radio frame), similarly tothe example illustrated in FIG. 14.

Setting Example 2 (Distributed Manner) of SLSS Block Set

Furthermore, FIG. 17 is an explanatory diagram for describing anotherexample of a setting method of the SLSS block set. Specifically, FIG. 17illustrates another example of a setting method of the SLSS block set ina case where the SLSS blocks are arranged in the time direction. In FIG.17, a horizontal axis represents a time. Furthermore, FIG. 17illustrates an example of a case where SLSS block sets #0 to #4 are set.Specifically, in the example illustrated in FIG. 17, for each of theSLSS block sets #0 to #3, each SLSS block set is set so that a series ofSLSS blocks are transmitted in a distributed manner, similarly to theexample illustrated in FIG. 15.

The terminal device 2 selects any one of the plurality of SLSS blocksets set in such a manner, and transmits the SLSS using the SLSS blockset. Furthermore, the terminal device 2 may select one or a plurality ofSLSS blocks of a plurality of SLSS blocks included in one selected SLSSblock set, and use the selected SLSS block for transmitting the SLSS.That is, the terminal device 2 may not necessarily use all the SLSSblocks included in the selected SLSS block set for transmitting theSLSS. For example, the number of SLSS blocks that the terminal device 2is to use for transmitting the SLSS may be determined according to thenumber and/or widths of beams implemented in the terminal device 2, acommunication environment (a center frequency and a bandwidth, ageographical location, a base station device coverage, a weather, and atraveling situation), an assumed use case (a requested quality ofservice (QoS) or a traffic type, and a requested situation from aperipheral communication device), and the like.

<Transmission Manner of SLSS Block>

Next, an example of a transmission method of the SLSS block will bedescribed. Note that in the present description, for convenience, unlessotherwise specified, it is assumed that a transmitting side of the SLSSblock is the terminal device 2 a and a receiving side of the SLSS blockis the terminal device 2 b.

(1) Combination of Cyclic Transmission and Transmission in RandomPattern

First, an example of a case of combining cyclic transmission andtransmission in a random pattern with each other when transmitting theSLSS block will be described. In this example, the SLSS is transmittedin a predetermined pattern in a certain cycle. However, in a case wherea cycle and a pattern substantially coincide among a plurality ofterminal devices, it becomes difficult for each of the plurality ofterminal devices to receive the SLSS transmitted from the other terminaldevices. Therefore, in this example, an SLSS block set to be used ischanged on the basis of a predetermined condition. As a specificexample, the terminal device 2 may change the SLSS block set to be usedon a regular basis. As such, the terminal device 2 switches a pattern inwhich the SLSS blocks are arranged in the regions to which the resourcesof the wireless communication are allocated, according to apredetermined condition.

In this example, information regarding at least one of an SLSS block setthat is being used by the terminal device 2 a or an SLSS block set thatis scheduled to be used next by the terminal device 2 a is included inthe SLSS block (PSBCH). As a specific example, notification of an indexof the SLSS block set is provided using the SLSS block. The terminaldevice 2 b that has received the SLSS block transmitted from theterminal device 2 a recognizes the index of the SLSS block set, attemptsto receive the SLSS at that timing, and does not perform transmission ofthe SLSS at that timing.

Furthermore, notification of the number of SLSS blocks transmitted fromthe terminal device 2 a (for example, the number of SLSS blocks in onecycle) may be provided by the PSBCH. An example of a notification methodincludes a notification by a bitmap. For example, FIG. 18 is anexplanatory diagram for describing a method of providing notification ofa use situation of the SLSS block by a bitmap. In an example illustratedin FIG. 18, 4-bit information associated with respective different bitsof SLSS blocks #0 to #3 is used as the bitmap. As a specific example, inthe example illustrated in FIG. 18, “0” is set for a bit associated withan SLSS block that is being used among the respective bits configuringthe bitmap, and “1” is set for a bit associated with an SLSS block thatis not being used among the respective bits. More specifically, in theexample illustrated in FIG. 18, only an SLSS block #2 of the SLSS blocks#0 to #3 is being used. Therefore, “0” is set for a bit associated withthe SLSS block #2 among the bits configuring the bitmap, and “1” is setfor the other bits.

Furthermore, notification of a direction of each beam may be provided bythe PSBCH. In this case, for example, notification of identificationinformation (that is, a terminal ID or an ID of the terminal device) ofthe terminal device 2, which is a transmission source, andidentification information (that is, a beam ID) of a beam may beprovided by PSSS/SSSS/PSBCH. Furthermore, as another example,notification of the number of SLSSs in one cycle may be provided usingthe PSBCH.

As such, the terminal device 2 notifies another terminal device 2 ofinformation regarding the switching of the pattern in a case where theterminal device 2 switches the pattern in which the SLSS blocks arearranged in the regions to which the resources of the wirelesscommunication are allocated. Note that a timing of the notification isnot particularly limited. As a specific example, the terminal device 2may notify another terminal device 2 of information regarding theswitching of the pattern in advance in a case where the switching of thepattern is scheduled. The advance notification of the pattern is anotification of a pattern for a predetermined transmission timing. It isdesirable that the predetermined transmission timing is the nexttransmission timing. Note that the advance notification of the patterncan be switched at an arbitrary transmission timing by includinginformation regarding a switching timing. Furthermore, as anotherexample, the terminal device 2 may notify another terminal device 2 ofinformation regarding the switching of the pattern after the switchingin a case where the terminal device 2 switches the pattern. Furthermore,when switching the pattern, the number of SLSSs in one cycle may bechanged. In this case, as described above, it is only required to notifyanother terminal device 2 of the number of SLSSs in one cycle after thechange of the pattern. Furthermore, when switching the pattern, asetting (localized manner or distributed manner) of the SLSS block setmay be changed.

(2) Request for SLSS Block on Demand

Next, an example of a case of requesting a sidelink synchronizationsignal (SLSS) block from a receiving side on demand will be described.In this example, a transmission resource of the SLSS block is determinedin response to the request from the terminal device 2 b on the receivingside to the terminal device 2 a on a transmitting side. Specifically,the terminal device 2 b on the receiving side transmits an on-demandSLSS block request to the terminal device 2 a on the transmitting side.At this time, the terminal device 2 b associates information regardingthe future reception timing with the on-demand SLSS block request. Theterminal device 2 a on the transmitting side transmits the SLSS block inconsideration of the future reception timing of the terminal device 2 bnotification of which is provided in association with the on-demand SLSSblock request from the terminal device 2 b.

The information included in the on-demand SLSS block request includesinformation regarding the future reception timing (that is, a timeresource in which the SLSS block may be transmitted). Note that theon-demand SLSS block request may include information regarding afrequency and a bandwidth of the future reception, information regardinga beam, position information of the terminal device, ID of the terminaldevice, and the like.

Examples of a physical channel used for a request for transmission ofthe SLSS block to the transmitting side, such as the on-demand SLSSblock request described above, or the like, include a PSSCH (sidelinkdata channel), a PSBCH (system information in the sidelink), and a PSDCH(channel for discovery), and the like.

It is desirable that the on-demand SLSS block request is transmitted ina designated section (on-demand SLSS block request window). It isdesirable that the on-demand SLSS block request window is common betweenthe terminal devices. In the on-demand SLSS block request window, it isdesirable that a terminal device other than a terminal device requestingthe on-demand SLSS block performs monitoring of the physical channel.Notification of the on-demand SLSS block request window is provided froma base station device, a local manager terminal, and a terminal deviceother than a terminal device requesting synchronization. A settingparameter of the on-demand SLSS block request window includes at least atime section and a cycle, and may also include information regarding afrequency resource and information regarding transmission and/orreception beams.

Furthermore, a frequency (a center frequency of a different carrier waveor a different operating band) different from a frequency used fortransmission of the SLSS block may be used for the request for thetransmission of the SLSS block. As a specific example, the request forthe transmission of the SLSS block using an operating band of a 60 GHzband may be transmitted using an operating band of a 6 GHz band.

(3) Control Based on Instruction from Base Station

Next, an example of a case where the transmission of the SLSS block iscontrolled on the basis of an instruction from the base station will bedescribed. In this example, the terminal device 2 a, which is thetransmitting side, transmits the SLSS block with an SLSS block set orpattern triggered by the base station device 1. Specifically,information regarding communication via the sidelink is transmitted toeach terminal device 2 by RRC signaling from the base station device 1.The terminal device 2 a on the transmitting side transmits the SLSSblock on the basis of an RRC setting notification of which is providedfrom the base station device 1. Furthermore, the terminal device 2 b onthe receiving side receives the SLSS block on the basis of the RRCsetting notification of which is provided from the base station device1.

<Local Manager Terminal>

Next, the local manager terminal will be described. The local managerterminal is a terminal device 2 that has authority regarding control ofthe communication via the sidelink, and can perform, for example, radioresource control of the local manager terminal itself and radio resourcecontrol (radio resource management) of another terminal around the localmanager terminal. For example, the local manager terminal can allocate aresource (or a resource pool) to another terminal device 2 amongresource pools given by the base station device 1. Furthermore, thelocal manager terminal may control the transmission of the SLSS byanother terminal device 2, similarly to a case of the base stationdescribed above.

The local manager terminal notifies (for example, broadcasts to) anotherterminal device 2 around the local manager terminal that it is a localmanager terminal. Note that it is preferable that the notification isbroadcast using, for example, a PSBCH. Another terminal device 2 that isnot the local manager terminal performs connection processing to thelocal manager terminal when it receives the SLSS block transmitted fromthe local manager terminal.

The local manager terminal can broadcast local system information (localSIB) to the terminal device 2 around the local manager terminal. Thelocal system information is broadcast using, for example, a PSSCH.Information included in the local system information includes thefollowing.

Information related to timing advance (timing advance measurementresource and the like)

Information regarding local resource (sub-resource pool, SLSS block,time division duplex (TDD) setting (uplink/downlink setting, slot formatand the like) information, and the like)

Local group ID (ID of local manager terminal, and the like)

Information regarding SLSS (information regarding SLSS block set andinformation regarding arrangement pattern of SLSS blocks)

Another terminal device 2 connected to the local manager terminalnotifies the local manager terminal of various information. The variousinformation includes, for example, a buffer status report (BSR) of thesidelink, RRM measurement results (an RSRP, an RSSI, a channel busyratio (CBR), a channel occupancy ratio (COR), and the like). The localmanager terminal may perform resource management of the sidelink on thebasis of the notification from another terminal device 2. Note that onelocal manager terminal is only required to exist for every predeterminedrange (for example, zone).

<Unicast Communication of Sidelink>

Next, an outline of unicast communication via the sidelink will bedescribed. In order to perform the unicast communication via thesidelink, adjustment of at least one of a transmission timing or areception timing is performed. An example of a method of adjusting thetransmission timing includes a method using timing advance.

(1) Solution 1

First, as solution 1, an example of a case of applying a timing advancevalue using a random access channel (RACH) procedure similar to that ofan uplink will be described. For example, FIG. 19 is a sequence diagramillustrating an example of a procedure related to establishment ofunicast communication via the sidelink, and illustrates an example of aprocedure corresponding to solution 1.

As illustrated in FIG. 19, an SLSS block is transmitted from theterminal device 2 a to another terminal device 2 (for example, theterminal device 2 b) located around the terminal device 2 a (S101). Theterminal device 2 b located around the terminal device 2 a receives theSLSS block transmitted from the terminal device 2 a, and performs framesynchronization with the terminal device 2 a on the basis of the SLSSblock (S103).

Next, the terminal device 2 b transmits a signal for timing advanceadjustment (for example, an SLSS, a PSDCH, a PRACH, a CSI-RS, an SRS, orthe like) corresponding to the received SLSS block to the terminaldevice 2 a at an appropriate timing, on the basis of control informationsuch as a PSBCH or the like. The terminal device 2 a estimates a timingadvance value on the basis of the signal for timing advance adjustmenttransmitted from the terminal device 2 b (S107), and notifies theterminal device 2 b of the timing advance value (S109). Specifically,the timing advance value is calculated from a time difference obtainedby (TRx−TTx)/2. Here, TRx is a reception timing of the signal for timingadvance adjustment, and TTx is a transmission timing of the signal fortiming advance adjustment. Note that it is preferable that the timingadvance value is unicast-transmitted and provided in notification to theterminal device 2 b, for example, by a PSSCH or the like.

Then, the terminal device 2 b performs timing adjustment based on thetiming advance value transmitted from the terminal device 2 a (S111)when transmitting data to the terminal device 2 a, and transmits data tothe terminal device 2 a by unicast communication (S113).

Hereinabove, as solution 1, the example of the case of applying thetiming advance value using the RACH procedure similar to that of theuplink has been described with reference to FIG. 19.

(2) Solution 2

Next, as Solution 2, an example of a case where a timing advance valueis applied on the basis of a difference between a frame synchronizationtiming common between terminal devices and a reception timing of an SLSSblock will be described. For example, FIG. 20 is a sequence diagramillustrating another example of a procedure related to establishment ofunicast communication via the sidelink, and illustrates an example of aprocedure corresponding to solution 2.

As illustrated in FIG. 20, the terminal devices 2 a and 2 b performframe synchronization based on a predetermined method. The framesynchronization is executed on the basis of, for example, a globalnavigation satellite system (GNSS), a downlink signal from the basestation device 1, an SLSS from the local manager terminal, or the like(S151).

Next, the terminal device 2 a transmits a signal (SLSS) for timingadvance adjustment to the terminal device 2 b at a frame timingaccording to a result of the frame synchronization (S153). The terminaldevice 2 b estimates a timing advance value on the basis of a differencebetween a reception timing of the signal for timing advance adjustmenttransmitted from the terminal device 2 a and the frame timing accordingto the result of the frame synchronization (S155). Specifically, thetiming advance value is calculated from a time difference obtained byTRx−Tframe. Here, TRx is the reception timing of the signal for timingadvance adjustment, and Tframe is a timing at a head of a frame in whichthe timing advance value is transmitted.

Then, the terminal device 2 b performs timing adjustment based on anestimation result of the timing advance value (S157) when transmittingdata to the terminal device 2 a, and transmits data to the terminaldevice 2 a by unicast communication (S159).

Hereinabove, as Solution 2, the example of the case where the timingadvance value is applied on the basis of the difference between theframe synchronization timing common between the terminal devices and thereception timing of the SLSS block has been described with reference toFIG. 20.

(3) Control Based on Instruction from Base Station

Hereinabove, an example of a case where the timing advance value forperforming the unicast communication between the terminal devices 2 aand 2 b via the sidelink is determined on the basis of the procedurebetween the terminal devices 2 a and 2 b has been described. On theother hand, the timing advance value for performing the unicastcommunication between the terminal devices 2 a and 2 b via the sidelinkmay be determined on the basis of an instruction from the base stationdevice 1. For example, when the terminal device 2 b transmits the datato the terminal device 2 a, the terminal device 2 b is only required toperform timing adjustment based on the timing advance value notificationof which is provided from the base station device 1 and then transmitthe data to the terminal device 2 a. Furthermore, the timing advancevalue may be determined on the basis of an instruction from the localmanager terminal instead of the base station device 1.

(4) Transmission Timing Switching of Link Between Terminal Devices ofUnicast Communication

In the terminal device 2, for example, a timing advance value is set foreach unicast link. Examples of a method of identifying the unicast linkinclude a method based on a transmission grant (sidelink grant) fromanother terminal device 2. It is preferable that the transmission grantis included in, for example, a PSCCH. Furthermore, as another example,the unicast link may be identified on the basis of a setting result of agrant-free resource for another terminal device 2. On the other hand,the terminal device 2 starts transmission at a timing of framesynchronization for broadcast.

As described above, the terminal device 2 may independently control atransmission timing of communication with destination designation suchas unicast and a transmission timing of communication withoutdestination designation such as broadcast. Note that the communicationwith destination designation such as the unicast corresponds to anexample of “first communication”, and a transmission timing of thecommunication corresponds to an example of a “first transmissiontiming”. Furthermore, the communication without destination designationsuch as the broadcast corresponds to an example of “secondcommunication”, and a transmission timing of the communicationcorresponds to an example of a “second transmission timing”.

(5) Change of Resource Pool According to Cast Type

A used resource pool may be changed according to a cast type ofcommunication between the terminal devices 2 via the sidelink.

<Example of Synchronization Between Terminal Devices>

Next, an example of synchronization between the terminal devices 2 thatperform inter-device communication (for example, V2V communication) viathe sidelink will be described.

As the synchronization between the terminal devices 2, “globalsynchronization”, “local synchronization”, and “hybrid synchronization”can be applied. The global synchronization is synchronization shared incommon between the terminal devices. An advantage of applying the globalsynchronization is that a timing of reservation or sensing of resourcesis aligned between all the terminal devices 2. The local synchronizationis synchronization shared between predetermined areas or betweenpredetermined terminal devices/terminal device groups. An advantage ofapplying the local synchronization is that a timing is aligned between aplurality of transmission/reception points. The hybrid synchronizationcorresponds to a combination of the global synchronization and the localsynchronization. As a specific example, the terminal device 2 appliesthe global synchronization to broadcast transmission such as an SLSS, aPSDCH, a PSCCH/PSSCH for transmitting broadcast information, or thelike, and applies the local synchronization to unicast communicationsuch as a PSCCH/PSSCH for transmitting unicast information, or the like.As another specific example, the terminal device 2 may apply the globalsynchronization to communication using a 6 GHz band or lower, andapplies the local synchronization to communication using a 6 GHz band orhigher. Furthermore, the local manager terminal (that is, the terminaldevice 2 having authority of resource control) is only required to beresponsible for the terminal device, which is the center of the localsynchronization.

<Example of Control According to Zone>

Next, an example of control of inter-device communication (for example,V2V communication) via the sidelink according to a region (hereinafter,also referred to as a “zone”) determined by a geographical position willbe described.

(1) Notification of Information for Setup

First, an example of a link setup method will be described. For example,a discovery signal may be used for link setup. As a specific example, itis only required to associate the discovery signal with link setupinformation (SIB) in an operating band of a millimeter wave band such as60 GHz and the like. Therefore, it becomes possible for the terminaldevice 2 that has received the discovery signal to perform the linksetup on the basis of the millimeter wave setup information associatedwith the discovery signal.

Furthermore, assist information for assisting the link setup in theoperating band of the millimeter wave band may be associated with aresponse to the discovery signal. Furthermore, the response may beassociated with position information of the terminal device 2 (forexample, the terminal device 2 that has received the discovery signal).

Furthermore, information regarding a capability (for example, supportband information in the millimeter wave operating band) or informationregarding the HD (for example, information regarding a transmissiontiming or a reception timing) may be associated with the discoverysignal or the response.

(2) Conventional Example (6 GHz)

Next, as a comparative example, a conventional example using a 6 GHzband will be described as an example of a procedure or a setting fordetermining a frequency or a band to be used according to a zone.

Specifically, the terminal device 2 first identifies a position of theterminal device 2 itself by using a GNSS or the like. Subsequently, theterminal device 2 determines a zone to which the terminal device 2itself belongs on the basis of information of the position of theterminal device 2 itself and a calculation equation of the zone. Then,the terminal device 2 performs transmission of a physical channel/signalof the sidelink using a frequency or a band associated with the zone towhich the terminal device 2 itself belongs.

For example, FIG. 21 is an explanatory diagram for describing an exampleof a relationship between a geographical position of the terminal deviceand a zone ID. In FIG. 21, for convenience, the geographical position isschematically illustrated by a horizontal axis (X axis) and a verticalaxis (Y axis). Furthermore, in an example illustrated in FIG. 21, eachregion set according to the geographical position is set as any one ofZone 0 to Zone 8.

An example of a calculation equation through which the terminal device 2calculates the zone ID on the basis of the geographical position isshown below as (Equation 1) to (Equation 3).[Math 1]x′=Ceil((x−x0)/L)Mod Nx  (Equation 1)y′=Ceil((y−y0)/W)Mod Ny  (Equation 2)Zone ID=g{x′,y′}  (Equation 3)

In the above (Equation 1) and (Equation 2), x and y are parametersindicating the geographical position of the terminal device 2. That is,x indicates a position of the terminal device 2 in an X-axis direction.Furthermore, y indicates a position of the terminal device 2 in a Y-axisdirection. Furthermore, in the above (Equation 1), x0 is informationindicating a reference position in the X-axis direction. Furthermore, Lis information indicating a width of each zone in the X-axis direction.Furthermore, Mod indicates an operator for calculating the remainder ofdivision. That is, a constant Nx is set according to how many zones areset along the X-axis direction. Furthermore, in the above (Equation 2),y0 is information indicating a reference position in the Y-axisdirection. Furthermore, W is information indicating a width of each zonein the Y-axis direction. Furthermore, a constant Ny is set according tohow many zones are set along the Y-axis direction. Furthermore, afunction g indicates a function for calculating the zone ID according toan input. For example, in (Equation 3), the function g is a function forcalculating the zone ID using x′ and y′ as variables. Note that each ofx0, y0, L, W, Nx, and Ny shown in the above (Equation 1) and (Equation2) is a parameter given in advance.

A more specific example of a calculation equation through which theterminal device 2 calculates the zone ID on the basis of thegeographical position is shown below as (Equation 4) to (Equation 6).[Math 2]x′=Ceil((x−x0)/L)Mod Nx  (Equation 4)y′=Ceil((y−y0)/W)Mod Ny  (Equation 5)Zone ID y′*Nx+x′  (Equation 6)

The above (Equation 4) and (Equation 5) are similar to theabovementioned (Equation 1) and (Equation 2). Furthermore, (Equation 6)corresponds to an example of a case where the function g is embodied inthe abovementioned (Equation 3).

Furthermore, FIG. 22 is a diagram illustrating an example of arelationship between the zone ID and an allocated frequency band. InFIG. 22, a horizontal axis represents a time, and a vertical axisrepresents a frequency. Furthermore, in the example illustrated in FIG.22, f1 to f8 correspond to indexes indicating predetermined frequencybands (for example, bandwidth parts (BWPs)). Here, in a case where theindex indicating the frequency band is f_id and the zone IDcorresponding to each zone is Zone_id, an index of a frequency band usedfor transmitting a signal of the sidelink is calculated by, for example,a calculation equation shown below as (Equation 7).[Math 3]f_id=Zone_id  (Equation 7)

(3) Example Case of Using Band of 6 GHz or Higher

Next, an example of processing and setting in a case of using a band of6 GHz or higher will be described. As described above, in a case ofusing the band of 6 GHz or higher (particularly, a millimeter wave bandsuch as 60 GHz or the like), the beamforming may be applied. Therefore,for the band of 6 GHz or higher, for example, a frequency or a band tobe used is only required to be determined according to a beam(direction) to be transmitted in addition to the zone.

As a specific example, the frequency or the band to be used may bedetermined on the basis of the zone ID or a beam ID. In this case, forexample, the frequency or the band may be reused according to acombination of the zone and a direction of the beam. With such control,it becomes possible to perform the frequency reuse (frequencyrepetition) in a narrower area, such that it becomes possible to improvearea frequency utilization efficiency.

In order to realize the control described above, for example, the basestation device 1 is only required to notify the terminal device 2 of afrequency table of the beamforming that can be used according to thezone and the direction. Furthermore, as another example, the frequencytable may be preset in the terminal device 2.

Furthermore, the beam (direction) may be determined in view of at leastone of elements exemplified below, for example.

Relative position between terminal device on transmitting side andterminal device on receiving side

Moving speed of terminal device on transmitting side

Moving speed of terminal device on receiving side

Width of beam

Number of antennas (antenna panels)

Furthermore, a width of the beam may be changed according to arelationship between the terminal device 2 on the transmitting side andthe terminal device 2 on the receiving side. As a specific example, thewidth of the beam may be changed according to a relative movingdirection or a relative moving speed between the terminal device 2 onthe transmitting side and the terminal device 2 on the receiving side.For example, in a case where the relative moving speed between theterminal device 2 on the transmitting side and the terminal device 2 onthe receiving side is high, it is desirable to use a beam having a largewidth.

For example, FIG. 23 is a diagram illustrating an example of arelationship among a zone ID, a beam ID, and a frequency band allocatedto transmission. In FIG. 23, for convenience, the geographical positionis schematically illustrated by a horizontal axis (X axis) and avertical axis (Y axis). Furthermore, in an example illustrated in FIG.23, each region set according to the geographical position is set as anyone of Zone 0 to Zone 8. Furthermore, in FIG. 23, #0 to #7 schematicallyindicate beam IDs of respective beams formed by each terminal device 2(for example, a vehicle). That is, in the example illustrated in FIG.23, different beam IDs are set for each of a plurality of beams formedtoward different directions. Furthermore, in FIG. 23, UE1 and UE2schematically indicate terminal devices 2 (for example, vehicles)different from each other.

Furthermore, FIG. 24 is a diagram illustrating an example of arelationship between a beam ID and a frequency band allocated totransmission, and illustrates an example of a setting related toallocation of a frequency band to the terminal device 2 illustrated asUE1 in FIG. 23. In FIG. 24, a horizontal axis represents a time, and avertical axis represents a frequency. Furthermore, in the exampleillustrated in FIG. 24, f0 to f7 correspond to indexes indicatingpredetermined frequency bands, similarly to the example illustrated inFIG. 22. That is, for the terminal device 2 illustrated as UE1,frequency bands with which the indexes f0 to f7 are associated areassociated, respectively, with respective beams corresponding to beamIDs #0 to #7.

On the other hand, FIG. 25 is a diagram illustrating another example ofa relationship between a beam ID and a frequency band allocated totransmission, and illustrates an example of a setting related toallocation of a frequency band to the terminal device 2 illustrated asUE2 in FIG. 23. In FIG. 25, a horizontal axis and a vertical axis aresimilar to those of the example illustrated in FIG. 24. Furthermore, inthe example illustrated in FIG. 25, f0 to f7 also correspond to indexesindicating predetermined frequency bands, similarly to the exampleillustrated in FIG. 24. That is, for the terminal device 2 illustratedas UE2, frequency bands with which the indexes f4 to f7 are associatedare associated, respectively, with respective beams corresponding tobeam IDs #0 to #4. Furthermore, frequency bands with which the indexesf0 to f3 are associated are associated, respectively, with respectivebeams corresponding to beam IDs #4 to #7.

Here, an example of a calculation equation for calculating the zone IDfrom the geographical position of the terminal device 2 and the beam(direction) will be described. For example, it is possible to calculatethe zone ID on the basis of a calculation equation shown below as(Equation 8) to (Equation 10). Note that (Equation 8) to (Equation 10)are substantially similar to the abovementioned (Equation 1) to(Equation 3), and a detailed description thereof will thus be omitted.[Math 4]x′=Ceil((x−x0)/L)Mod Nx  (Equation 8)y′=Ceil((y−y0)/W)Mod Ny  (Equation 9)Zone ID=g{x′,y′}  (Equation 10)

Furthermore, an index of a frequency band used for transmission of datais calculated by, for example, a calculation equation shown below as(Equation 11).[Math 5]f_id=f{Zone_id,beam_id}  (Equation 11)

In the above (Equation 11), beam_id is an index indicating the directionof the beam. Furthermore, a function f indicates a function forcalculating the index of the frequency band used for transmission ofdata according to an input. For example, in (Equation 11), the functionf is a function for calculating the index of the frequency band used fortransmission using the zone ID and the index indicating the direction ofthe beam as variables. As a specific example of the function f, it iscalculated by a calculation equation illustrated below (Equation 12).Note that in (Equation 12) shown below, Nf is a total number of indexesof frequency bands.[Math 6]f _(id)=Zone_(id)+beam_id Mod Nf  (Equation 12)

Hereinabove, the example of the control of the inter-devicecommunication (for example, the V2V communication) via the sidelinkaccording to the region (zone) determined by the geographical positionhas been described.

4. Application Example

The technology according to the present disclosure can be applied tovarious products. For example, the base station device 1 may be realizedas any kind of evolved Node B (eNB) such as a macro eNB, a small eNB, orthe like. The small eNB may be an eNB that covers a cell smaller than amacro cell, such as a pico eNB, a micro eNB, a home (femto) eNB, or thelike. Instead, the base station device 1 may be realized as another typeof base station such as a Node B, a base transceiver station (BTS), orthe like. The base station device 1 may include a main body (alsoreferred to as a base station device) that controls wirelesscommunication and one or more remote radio heads (RRHs) that arearranged at a place different from the main body. Furthermore, varioustypes of terminals as described later may operate as the base stationdevice 1 by temporarily or semi-permanently executing a base stationfunction. Moreover, at least some components of the base station device1 may be realized in the base station device or a module for the basestation device.

Furthermore, for example, the terminal device 2 may be realized as asmartphone, a tablet personal computer (PC), a laptop PC, a portablegame terminal, a mobile terminal such as a portable/dongle-type mobilerouter, a digital camera, or the like, or an in-vehicle terminal such asa car navigation device or the like. Furthermore, the terminal device 2may be realized as a terminal (also referred to as a machine typecommunication (MTC) terminal) that performs machine to machine (M2M)communication. Moreover, at least some components of the terminal device2 may be realized in a module (for example, an integrated circuit moduleincluding one die) mounted in these terminals.

<4.1. Application Example Related to Base Station>

First Application Example

FIG. 26 is a block diagram illustrating a first example of a schematicconfiguration of an eNB to which the technology according to the presentdisclosure can be applied. The eNB 800 includes one or more antennas 810and a base station device 820. Each antenna 810 and the base stationdevice 820 can be connected to each other via a radio frequency (RF)cable.

Each of the antennas 810 has a single or a plurality of antenna elements(for example, a plurality of antenna elements configuring amultiple-input multiple-output (MIMO) antenna), and is used to transmitand receive a radio signal by the base station device 820. The eNB 800includes a plurality of antennas 810 as illustrated in FIG. 26, and theplurality of antennas 810 may correspond to, for example, a plurality offrequency bands used by the eNB 800, respectively. Note that an examplein which the eNB 800 includes the plurality of antennas 810 has beenillustrated in FIG. 26, but the eNB 800 may include a single antenna810.

The base station device 820 includes a controller 821, a memory 822, anetwork interface 823, and a wireless communication interface 825.

The controller 821 may be, for example, a central processing unit (CPU)or a digital signal processor (DSP) and operates various functions of anupper layer of the base station device 820. For example, the controller821 generates a data packet from data in a signal processed by thewireless communication interface 825 and transfers the generated datapacket via the network interface 823. The controller 821 may generate abundled packet by bundling data from a plurality of baseband processorsand transfer the generated bundled packet. Furthermore, the controller821 may have a logical function of executing control such as radioresource control, radio bearer control, mobility management, admissioncontrol, scheduling, or the like. Furthermore, the control may beexecuted in cooperation with a peripheral eNB or a core network node.The memory 822 includes a random access memory (RAM) and a read onlymemory (ROM), and stores a program executed by the controller 821 andvarious control data (for example, terminal list, transmission powerdata, scheduling data, and the like).

The network interface 823 is a communication interface for connectingthe base station device 820 to a core network 824. The controller 821may communicate with the core network node or another eNB via networkinterface 823. In that case, the eNB 800 and the core network node oranother eNB may be connected to each other by a logical interface (forexample, an S1 interface or an X2 interface). The network interface 823may be a wired communication interface or a wireless communicationinterface for a wireless backhaul. In a case where the network interface823 is the wireless communication interface, the network interface 823may use a frequency band higher than a frequency band used by thewireless communication interface 825 for wireless communication.

The wireless communication interface 825 supports any one cellularcommunication manner such as long term evolution (LTE), LTE-Advanced orthe like, and provides a wireless connection to a terminal located in acell of the eNB 800 via the antenna 810. The wireless communicationinterface 825 can typically include a baseband (BB) processor 826, aradio frequency (RF) circuit 827, and the like. The BB processor 826 mayperform, for example, coding/decoding, modulation/demodulation,multiplexing/demultiplexing, and the like, and executes various signalprocessing of each layer (for example, L1, medium access control (MAC),radio link control (RLC), and packet data convergence protocol (PDCP)).The BB processor 826 may have some or all of the logical functionsdescribed above instead of the controller 821. The BB processor 826 maybe a module including a memory that stores a communication controlprogram, a processor that executes the communication control program,and a related circuit, and a function of the BB processor 826 may bechangeable by updating the communication control program. Furthermore,the module may be a card or a blade inserted into a slot of the basestation device 820 or may be a chip mounted on the card or the blade.Meanwhile, the RF circuit 827 may include a mixer, a filter, anamplifier, and the like, and transmits and receives a radio signal viathe antenna 810.

The wireless communication interface 825 includes a plurality of BBprocessors 826 as illustrated in FIG. 26, and the plurality of BBprocessors 826 may correspond to, for example, the plurality offrequency bands used by the eNB 800, respectively. Furthermore, thewireless communication interface 825 includes a plurality of RF circuits827 as illustrated in FIG. 26, and the plurality of RF circuits 827 maycorrespond to, for example, the plurality of antenna elements,respectively. Note that an example in which the wireless communicationinterface 825 includes the plurality of BB processors 826 and theplurality of RF circuits 827 has been illustrated in FIG. 26, but thewireless communication interface 825 may include a single BB processor826 or a single RF circuit 827.

In the eNB 800 illustrated in FIG. 26, one or more components of theupper layer processing unit 101 and the control unit 103 described withreference to FIG. 2 may be implemented in the wireless communicationinterface 825. Alternatively, at least some of these components may beimplemented in the controller 821. As an example, the eNB 800 may bemounted with a module including a part (for example, the BB processor826) or the whole of the wireless communication interface 825 and/or thecontroller 821, and the one or more components may be implemented in themodule. In this case, the module may store a program for causing aprocessor to function as the one or more components (in other words, aprogram for causing the processor to execute operations of the one ormore components), and execute the program. As another example, theprogram for causing the processor to function as the one or morecomponents may be installed in the eNB 800, and the wirelesscommunication interface 825 (for example, the BB processor 826) and/orthe controller 821 may execute the program. As described above, the eNB800, the base station device 820, or the module may be provided or theprogram for causing the processor to function as the one or morecomponents may be provided, as a device including the one or morecomponents. Furthermore, a readable recording medium on which theprogram is recorded may be provided.

Furthermore, in the eNB 800 illustrated in FIG. 26, the reception unit105 and the transmission unit 107 described with reference to FIG. 2 maybe implemented in the wireless communication interface 825 (for example,the RF circuit 827). Furthermore, the transmission/reception antenna 109may be implemented in the antenna 810.

Second Application Example

FIG. 27 is a block diagram illustrating a second example of a schematicconfiguration of an eNB to which the technology according to the presentdisclosure can be applied. The eNB 830 includes one or more antennas840, a base station device 850, and an RRH 860. Each antenna 840 and theRRH 860 can be connected to each other via a RF cable. Furthermore, thebase station device 850 and the RRH 860 can be connected to each otherby a high-speed line such as an optical fiber cable or the like.

Each of the antennas 840 has a single or a plurality of antenna elements(for example, a plurality of antenna elements configuring a MIMOantenna), and is used to transmit and receive a radio signal by the RRH860. The eNB 830 includes a plurality of antennas 840 as illustrated inFIG. 27, and the plurality of antennas 840 may correspond to, forexample, a plurality of frequency bands used by the eNB 830,respectively. Note that an example in which the eNB 830 includes theplurality of antennas 840 has been illustrated in FIG. 27, but the eNB830 may include a single antenna 840.

The base station device 850 includes a controller 851, a memory 852, anetwork interface 853, a wireless communication interface 855, and aconnection interface 857. The controller 851, the memory 852, and thenetwork interface 853 are similar to the controller 821, the memory 822,and the network interface 823 described with reference to FIG. 26,respectively.

The wireless communication interface 855 supports any one cellularcommunication manner such as LTE, LTE-Advanced or the like, and providesa wireless connection to a terminal located in a sector corresponding tothe RRH 860 via the RRH 860 and the antenna 840. The wirelesscommunication interface 855 may typically include a BB processor 856 andthe like. The BB processor 856 is similar to the BB processor 826described with reference to FIG. 26 except that it is connected to an RFcircuit 864 of the RRH 860 via the connection interface 857. Thewireless communication interface 855 includes a plurality of BBprocessors 856 as illustrated in FIG. 26, and the plurality of BBprocessors 856 may correspond to, for example, the plurality offrequency bands used by the eNB 830, respectively. Note that an examplein which the wireless communication interface 855 includes the pluralityof BB processors 856 has been illustrated in FIG. 27, but the wirelesscommunication interface 855 may include a single BB processor 856.

The connection interface 857 is an interface for connecting the basestation device 850 (wireless communication interface 855) to the RRH860. The connection interface 857 may be a communication module forcommunication on the high-speed line connecting the base station device850 (wireless communication interface 855) and the RRH 860 to eachother.

Furthermore, the RRH 860 also includes a connection interface 861 and awireless communication interface 863.

The connection interface 861 is an interface for connecting the RRH 860(wireless communication interface 863) to the base station device 850.The connection interface 861 may be a communication module forcommunication on the high-speed line.

The wireless communication interface 863 transmits and receives a radiosignal via the antenna 840. The wireless communication interface 863 maytypically include an RF circuit 864 and the like. The RF circuit 864 mayinclude a mixer, a filter, an amplifier, and the like, and transmits andreceives a radio signal via the antenna 840. The wireless communicationinterface 863 includes a plurality of RF circuits 864 as illustrated inFIG. 27, and the plurality of RF circuits 864 may correspond to, forexample, the plurality of antenna elements, respectively. Note that anexample in which the wireless communication interface 863 includes theplurality of RF circuits 864 has been illustrated in FIG. 27, but thewireless communication interface 863 may include a single RF circuit864.

In the eNB 830 illustrated in FIG. 27, one or more components of theupper layer processing unit 101 and the control unit 103 described withreference to FIG. 2 may be implemented in the wireless communicationinterface 855 and/or the wireless communication interface 863.Alternatively, at least some of these components may be implemented inthe controller 851. As an example, the eNB 830 may be mounted with amodule including a part (for example, the BB processor 856) or the wholeof the wireless communication interface 855 and/or the controller 851,and the one or more components may be implemented in the module. In thiscase, the module may store a program for causing a processor to functionas the one or more components (in other words, a program for causing theprocessor to execute operations of the one or more components), andexecute the program. As another example, the program for causing theprocessor to function as the one or more components may be installed inthe eNB 830, and the wireless communication interface 855 (for example,the BB processor 856) and/or the controller 851 may execute the program.As described above, the eNB 830, the base station device 850, or themodule may be provided or the program for causing the processor tofunction as the one or more components may be provided, as a deviceincluding the one or more components. Furthermore, a readable recordingmedium on which the program is recorded may be provided.

Furthermore, in the eNB 830 illustrated in FIG. 27, for example, thereception unit 105 and the transmission unit 107 described withreference to FIG. 2 may be implemented in the wireless communicationinterface 863 (for example, the RF circuit 864). Furthermore, thetransmission/reception antenna 109 may be implemented in the antenna840.

<4.2. Application Example Related to Terminal Device>

First Application Example

FIG. 28 is a block diagram illustrating an example of a schematicconfiguration of a smartphone 900 to which the technology according tothe present disclosure can be applied. The smartphone 900 includes aprocessor 901, a memory 902, a storage 903, an external connectioninterface 904, a camera 906, a sensor 907, a microphone 908, an inputdevice 909, a display device 910, a speaker 911, a wirelesscommunication interface 912, one or more antenna switches 915, one ormore antennas 916, a bus 917, a battery 918, and an auxiliary controller919.

The processor 901 may be, for example, a CPU or a system on chip (SoC),and controls functions of an application layer and other layers of thesmartphone 900. The memory 902 includes a RAM and a ROM, and stores aprogram executed by the processor 901 and data. The storage 903 caninclude a storage medium such as a semiconductor memory, a hard disk orthe like. The external connection interface 904 is an interface forconnecting an externally attached device such as a memory card, auniversal serial bus (USB) device or the like to the smartphone 900.

The camera 906 includes, for example, an imaging element such as acharge coupled device (CCD), a complementary metal oxide semiconductor(CMOS), or the like, and generates a captured image. The sensor 907 caninclude a sensor group such as, for example, a positioning sensor, agyro sensor, a geomagnetic sensor, an acceleration sensor, and the like.The microphone 908 converts a sound input into the smartphone 900 to anaudio signal. The input device 909 includes, for example, a touch sensorthat detects a touch on a screen of the display device 910, a keypad, akeyboard, a button, a switch, or the like, and accepts an operation oran information input from a user. The display device 910 includes ascreen such as a liquid crystal display (LCD), an organic light emittingdiode (OLED) display, or the like, and displays an output image of thesmartphone 900. The speaker 911 converts an audio signal output from thesmartphone 900 to a sound.

The wireless communication interface 912 supports any one cellularcommunication manner such as LTE, LTE-Advanced, or the like, andexecutes wireless communication. The wireless communication interface912 can typically include a BB processor 913, an RF circuit 914, and thelike. The BB processor 913 may perform, for example, coding/decoding,modulation/demodulation, multiplexing/demultiplexing, and the like, andperforms various signal processing for wireless communication.Meanwhile, the RF circuit 914 may include a mixer, a filter, anamplifier, and the like, and transmits and receives a radio signal viathe antenna 916. The wireless communication interface 912 may be aone-chip module in which the BB processor 913 and the RF circuit 914 areintegrated. The wireless communication interface 912 may include aplurality of BB processors 913 and a plurality of RF circuits 914 asillustrated in FIG. 28. Note that an example in which the wirelesscommunication interface 912 includes the plurality of BB processors 913and the plurality of RF circuits 914 has been illustrated in FIG. 28,but the wireless communication interface 912 may include a single BBprocessor 913 or a single RF circuit 914.

Moreover, the wireless communication interface 912 may support othertypes of wireless communication manners such as a short-range wirelesscommunication manner, a near field wireless communication manner, awireless local area network (LAN) manner, or the like, in addition tothe cellular communication manner. In that case, the wirelesscommunication interface 912 may include the BB processor 913 and the RFcircuit 914 for every wireless communication manner.

Each of the antenna switches 915 switches a connection destination ofthe antenna 916 among a plurality of circuits (for example, circuits fordifferent wireless communication manners) included in the wirelesscommunication interface 912.

Each of the antennas 916 has a single or a plurality of antenna elements(for example, a plurality of antenna elements configuring a MIMOantenna), and is used to transmit and receive a radio signal by thewireless communication interface 912. The smartphone 900 may include aplurality of antennas 916 as illustrated in FIG. 28. Note that anexample in which the smartphone 900 includes the plurality of antennas916 has been illustrated in FIG. 28, but the smartphone 900 may includea single antenna 916.

Moreover, the smartphone 900 may include the antenna 916 for everywireless communication manner. In that case, the antenna switch 915 maybe omitted from the configuration of the smartphone 900.

The bus 917 connects the processor 901, the memory 902, the storage 903,the external connection interface 904, the camera 906, the sensor 907,the microphone 908, the input device 909, the display device 910, thespeaker 911, the wireless communication interface 912, and the auxiliarycontroller 919 to each other. The battery 918 supplies power to eachblock of the smartphone 900 illustrated in FIG. 28 via a feeder linepartially illustrated as a broken line in FIG. 28. The auxiliarycontroller 919 operates a minimum necessary function of the smartphone900 in, for example, a sleep mode.

In the smartphone 900 illustrated in FIG. 28, one or more components ofthe upper layer processing unit 201 and the control unit 203 describedwith reference to FIG. 3 may be implemented in the wirelesscommunication interface 912. Alternatively, at least some of thesecomponents may be implemented in the processor 901 or the auxiliarycontroller 919. As an example, the smartphone 900 may be mounted with amodule including a part (for example, the BB processor 913) or the wholeof the wireless communication interface 912, the processor 901, and/orthe auxiliary controller 919, and the one or more components may beimplemented in the module. In this case, the module may store a programfor causing a processor to function as the one or more components (inother words, a program for causing the processor to execute operationsof the one or more components), and execute the program. As anotherexample, the program for causing the processor to function as the one ormore components may be installed in the smartphone 900, and the wirelesscommunication interface 912 (for example, the BB processor 913), theprocessor 901, and/or the auxiliary controller 919 may execute theprogram. As described above, the smartphone 900 or the module may beprovided or the program for causing the processor to function as the oneor more components may be provided, as a device including the one ormore components. Furthermore, a readable recording medium on which theprogram is recorded may be provided.

Furthermore, in the smartphone 900 illustrated in FIG. 28, for example,the reception unit 205 and the transmission unit 207 described withreference to FIG. 3 may be implemented in the wireless communicationinterface 912 (for example, the RF circuit 914). Furthermore, thetransmission/reception antenna 209 may be implemented in the antenna916.

Second Application Example

FIG. 29 is a block diagram illustrating an example of a schematicconfiguration of a car navigation device 920 to which the technologyaccording to the present disclosure can be applied. The car navigationdevice 920 includes a processor 921, a memory 922, a global positioningsystem (GPS) module 924, a sensor 925, a data interface 926, a contentplayer 927, a storage medium interface 928, an input device 929, adisplay device 930, a speaker 931, a wireless communication interface933, one or more antenna switches 936, one or more antennas 937, and abattery 938.

The processor 921 may be, for example, a CPU or an SoC, and controls anavigation function and the other functions of the car navigation device920. The memory 922 includes a RAM and a ROM, and stores a programexecuted by the processor 921 and data.

The GPS module 924 measures a position (for example, a latitude, alongitude, and an altitude) of the car navigation device 920 using a GPSsignal received from a GPS satellite. The sensor 925 can include asensor group such as, for example, a gyro sensor, a geomagnetic sensor,a barometric sensor, and the like. The data interface 926 is, forexample, connected to an in-vehicle network 941 via a terminal (notillustrated), and acquires data such as vehicle speed data or the likegenerated on a vehicle side.

The content player 927 plays a content stored in a storage medium (forexample, a compact disk (CD) or a digital versatile disk (DVD)) insertedinto the storage medium interface 928. The input device 929 includes,for example, a touch sensor that detects a touch on a screen of thedisplay device 930, a button, a switch, or the like, and accepts anoperation or an information input from a user. The display device 930includes a screen such as an LCD, an OLED display or the like, anddisplays an image of a navigation function or the played content. Thespeaker 931 outputs a sound of the navigation function or the playedcontent.

The wireless communication interface 933 supports any one cellularcommunication manner such as LTE, LTE-Advanced, or the like, andexecutes wireless communication. The wireless communication interface933 can typically include a BB processor 934, an RF circuit 935, and thelike. The BB processor 934 may perform, for example, coding/decoding,modulation/demodulation, multiplexing/demultiplexing, and the like, andperforms various signal processing for wireless communication.Meanwhile, the RF circuit 935 may include a mixer, a filter, anamplifier, and the like, and transmits and receives a radio signal viathe antenna 937. The wireless communication interface 933 may be aone-chip module in which the BB processor 934 and the RF circuit 935 areintegrated. The wireless communication interface 933 may include aplurality of BB processors 934 and a plurality of RF circuits 935 asillustrated in FIG. 29. Note that an example in which the wirelesscommunication interface 933 includes the plurality of BB processors 934and the plurality of RF circuits 935 has been illustrated in FIG. 29,but the wireless communication interface 933 may include a single BBprocessor 934 or a single RF circuit 935.

Moreover, the wireless communication interface 933 may support othertypes of wireless communication manners such as a short-range wirelesscommunication manner, a near field wireless communication manner, awireless LAN manner, or the like, in addition to the cellularcommunication manner. In that case, the wireless communication interface933 may include the BB processor 934 and the RF circuit 935 for everywireless communication manner.

Each of the antenna switches 936 switches a connection destination ofthe antenna 937 among a plurality of circuits (for example, circuits fordifferent wireless communication manners) included in the wirelesscommunication interface 933.

Each of the antennas 937 has a single or a plurality of antenna elements(for example, a plurality of antenna elements configuring a MIMOantenna), and is used to transmit and receive a radio signal by thewireless communication interface 933. The car navigation device 920 mayinclude a plurality of antennas 937 as illustrated in FIG. 29. Note thatan example in which the car navigation device 920 includes the pluralityof antennas 937 has been illustrated in FIG. 29, but the car navigationdevice 920 may include a single antenna 937.

Moreover, the car navigation device 920 may include the antenna 937 forevery wireless communication manner. In that case, the antenna switch936 may be omitted from the configuration of the car navigation device920.

The battery 938 supplies power to each block of the car navigationdevice 920 illustrated in FIG. 29 via a feeder line partiallyillustrated as a broken line in FIG. 29. Furthermore, the battery 938accumulates power supplied from the vehicle side.

In the car navigation device 920 illustrated in FIG. 29, one or morecomponents of the upper layer processing unit 201 and the control unit203 described with reference to FIG. 3 may be implemented in thewireless communication interface 933. Alternatively, at least some ofthese components may be implemented in the processor 921. As an example,the car navigation device 920 may be mounted with a module including apart (for example, the BB processor 934) or the whole of the wirelesscommunication interface 933 and/or the processor 921, and the one ormore components may be implemented in the module. In this case, themodule may store a program for causing a processor to function as theone or more components (in other words, a program for causing theprocessor to execute operations of the one or more components), andexecute the program. As another example, the program for causing theprocessor to function as the one or more components may be installed inthe car navigation device 920, and the wireless communication interface933 (for example, the BB processor 934) and/or the processor 921 mayexecute the program. As described above, the car navigation device 920or the module may be provided or the program for causing the processorto function as the one or more components may be provided, as a deviceincluding the one or more components. Furthermore, a readable recordingmedium on which the program is recorded may be provided.

Furthermore, in the car navigation device 920 illustrated in FIG. 29,for example, the reception unit 205 and the transmission unit 207described with reference to FIG. 3 may be implemented in the wirelesscommunication interface 933 (for example, the RF circuit 935).Furthermore, the transmission/reception antenna 209 may be implementedin the antenna 937.

Furthermore, the technology according to the present disclosure may alsobe realized as an in-vehicle system (or a vehicle) 940 including one ormore blocks of the car navigation device 920 described above, thein-vehicle network 941, and a vehicle side module 942. That is, thein-vehicle system (or the vehicle) 940 may be provided as a deviceincluding at least one of the upper layer processing unit 201, thecontrol unit 203, the reception unit 205, or the transmission unit 207.The vehicle side module 942 generates vehicle side data such as avehicle speed, an engine speed, trouble information, or the like, andoutputs the generated data to the in-vehicle network 941.

5. End

As described above, in the system according to the embodiment of thepresent disclosure, a communication device includes a communication unitthat performs wireless communication and a control unit that controlsinter-device communication between different terminal devices. Thecontrol unit performs control so that a plurality of synchronizationsignals associated with each of a plurality of beams allocated to beavailable for the inter-device communication is patterned and arrangedin regions to which resources of the wireless communication areallocated and is transmitted to another terminal device. Furthermore,the control unit performs control so that a pattern in which theplurality of synchronization signals is arranged is switched accordingto a predetermined condition.

With the configuration as described above, according to the systemaccording to the embodiment of the present disclosure, it becomespossible to establish inter-terminal communication between terminaldevices more rapidly even in a situation with beam connection under theHD restriction like inter-terminal communication (for example, V2Xcommunication typified by V2V) in which application of NR is assumed.That is, according to the system according to the embodiment of thepresent disclosure, it becomes possible to realize the establishment ofthe inter-terminal communication in which the application of the NR isassumed, in a more suitable manner.

Furthermore, in the system according to the embodiment of the presentdisclosure, a communication device includes a communication unit thatperforms wireless communication and a control unit that controlsinter-device communication between different terminal devices. Thecontrol unit independently controls a first transmission timing of firstcommunication (for example, unicast) with destination designation and asecond transmission timing of second communication (for example,broadcast) without destination designation among the inter-devicecommunication.

With the configuration as described above, according to the systemaccording to the embodiment of the present disclosure, it becomespossible to establish communication with destination designation such asthe unicast more rapidly in inter-terminal communication (for example,V2X communication typified by V2V) in which application of NR isassumed. That is, according to the system according to the embodiment ofthe present disclosure, it becomes possible to realize the establishmentof the inter-terminal communication in which the application of the NRis assumed, in a more suitable manner.

Hereinabove, the preferred embodiments of the present disclosure havebeen described in detail with reference to the accompanying drawings,but a technical scope of the present disclosure is not limited to suchexamples. It will be apparent to those skilled in the art of the presentdisclosure that various modifications or alterations can be conceivedwithin the scope of the technical idea described in the claims, and itis naturally understood that these modifications or alterations alsofall within the technical scope of the present disclosure.

Furthermore, the effects described in the present specification aremerely illustrative or exemplary rather than being restrictive. That is,the technology according to the present disclosure can accomplish othereffects apparent to those skilled in the art from the description of thepresent specification, in addition to or instead of the effectsdescribed above.

Note that the following configurations also fall within the technicalscope of the present disclosure.

(1)

A communication device including:

a communication unit that performs wireless communication; and

a control unit that performs control so that a plurality ofsynchronization signals is patterned and arranged in regions to whichresources of the wireless communication are allocated and is transmittedto another terminal device, the plurality of synchronization signalsbeing associated with each of a plurality of beams allocated to beavailable for inter-device communication between different terminaldevices,

in which the control unit performs control so that a pattern in whichthe plurality of synchronization signals is arranged is switchedaccording to a predetermined condition.

(2)

The communication device according to the above (1), in which thecontrol unit performs control so that notification of informationregarding the pattern after being switched is provided to the anotherterminal device.

(3)

The communication device according to the above (2), in which thecontrol unit performs control so that notification of the informationregarding the pattern after being switched is provided to the anotherterminal device, in a case where the pattern is switched.

(4)

The communication device according to the above (2) or (3), in which thecontrol unit

performs control so that the pattern is switched at a predeterminedtiming, and

performs control so that notification of the information regarding thepattern after being switched is provided to the another terminal devicesbefore the pattern is switched.

(5)

The communication device according to any one of the above (2) to (4),in which the information regarding the pattern after being switchedincludes at least one of

-   -   information regarding the beam associated with each of the        plurality of synchronization signals,    -   information regarding a terminal device of a transmission        source, or    -   information regarding the number of synchronization signals        transmitted in one cycle.

(6)

The communication device according to any one of the above (2) to (5),in which the control unit performs control so that notification ofinformation in which the pattern is indicated by a bitmap is provided tothe another terminal device as the information regarding the patternafter being switched.

(7)

The communication device according to any one of the above (1) to (6),in which the control unit performs control so that the pattern isswitched on the basis of an instruction from another communicationdevice.

(8)

The communication device according to the above (7), in which theanother communication device is a base station.

(9)

The communication device according to the above (7), in which theanother communication device is another terminal device having authorityregarding control of the inter-device communication.

(10)

The communication device according to any one of the above (1) to (9),in which the control unit performs control so that the pattern isswitched on the basis of a request from the another terminal device.

(11)

The communication device according to the above (10), in which thecontrol unit performs control so that the pattern is switched accordingto a reception timing of the another terminal device in the inter-devicecommunication.

(12)

The communication device according to any one of the above (1) to (11),in which the control unit

sets a plurality of synchronization signal sets with which the pluralityof synchronization signals is associated, respectively, and

performs control so that the pattern in which the plurality ofsynchronization signals is arranged is switched by switching thesynchronization signal set used for transmitting the plurality ofsynchronization signals to the another terminal device.

(13)

The communication device according to any one of the above (1) to (12),in which a timing advance value for the another terminal device todesignate a destination and transmit data by the inter-devicecommunication is calculated on the basis of a synchronization signalselected by the another terminal device among the plurality ofsynchronization signals.

(14)

The communication device according to the above (13), in which thecontrol unit

performs control so that a signal for timing advance adjustmentcorresponding to the synchronization signal selected by the anotherterminal device is received from the another terminal device, and

performs control so that the timing advance value according to areception result of the signal

(15)

The communication device according to the above (13),

in which the control unit

-   -   performs frame synchronization with the another terminal device        on the basis of a reception result of a predetermined signal,        and    -   performs control so that a signal for timing advance adjustment        is transmitted to the another terminal device as the        synchronization signal at a timing according to a result of the        frame synchronization, and

the timing advance value is calculated on the basis of a receptionresult of the signal for timing advance adjustment by the anotherterminal device.

(16)

The communication device according to the above (15), in which thecontrol unit performs control so that the frame synchronization isperformed on the basis of at least one of a global navigation satellitesystem (GNSS) signal, a downlink signal transmitted from a base station,or a signal transmitted from a terminal device having authorityregarding control of the inter-device communication.

(17)

The communication device according to any one of the above (1) to (16),in which the control unit controls the number of the plurality ofsynchronization signals according to a predetermined condition when thepattern is switched.

(18)

The communication device according to any one of the above (1) to (17),in which the control unit controls allocation of resources for theanother terminal device to transmit data via the inter-devicecommunication.

(19)

The communication device according to any one of the above (1) to (18),in which the inter-device communication is communication based on acommunication manner of switching and performing transmission andreception in a time division manner.

(20)

A communication device including:

a communication unit that performs wireless communication; and

a control unit performs control so that a plurality of synchronizationsignals transmitted another terminal device and associated with each ofa plurality of beams allocated to be available for inter-devicecommunication between different terminal devices is received,

in which the control unit performs control so that information regardingswitching of a pattern in which the plurality of synchronization signalsis arranged in regions to which resources of the wireless communicationare allocated is acquired from the another terminal device, in a casewhere the pattern is switched.

(21)

A communication method executed by a computer, including:

performing wireless communication;

performing control so that a plurality of synchronization signals ispatterned and arranged in regions to which resources of the wirelesscommunication are allocated and is transmitted to another terminaldevice, the plurality of synchronization signals being associated witheach of a plurality of beams allocated to be available for inter-devicecommunication between different terminal devices; and

performing control so that a pattern in which the plurality ofsynchronization signals is arranged is switched according to apredetermined condition.

(22)

A communication method executed by a computer, including:

performing wireless communication;

performing control so that a plurality of synchronization signalstransmitted from another terminal device and associated with each of aplurality of beams allocated to be available for inter-devicecommunication between different terminal devices is received; and

performing control so that information regarding switching of a patternin which the plurality of synchronization signals is arranged in regionsto which resources of the wireless communication are allocated isacquired from the another terminal device, in a case where the patternis switched.

(23)

A program for causing a computer to execute the following steps of:

performing wireless communication;

performing control so that a plurality of synchronization signals ispatterned and arranged in regions to which resources of the wirelesscommunication are allocated and is transmitted to another terminaldevice, the plurality of synchronization signals being associated witheach of a plurality of beams allocated to be available for inter-devicecommunication between different terminal devices; and

performing control so that a pattern in which the plurality ofsynchronization signals is arranged is switched according to apredetermined condition.

(24)

A program for causing a computer to execute the following steps of:

performing wireless communication;

performing control so that a plurality of synchronization signalstransmitted from another terminal device and associated with each of aplurality of beams allocated to be available for inter-devicecommunication between different terminal devices is received; and

performing control so that information regarding switching of a patternin which the plurality of synchronization signals is arranged in regionsto which resources of the wireless communication are allocated isacquired from the another terminal device, in a case where the patternis switched.

(25)

A communication device including:

a communication unit that performs wireless communication; and

a control unit that independently controls a first transmission timingof first communication with destination designation and a secondtransmission timing of second communication without destinationdesignation among inter-device communication between different terminaldevices.

(26)

The communication device according to the above (25),

in which the communication device is a terminal device, and

the control unit controls the first transmission timing related to datatransmission to another terminal device based on the firstcommunication.

(27)

The communication device according to the above (26), in which thecontrol unit

-   -   calculates a timing advance value on the basis of a reception        result of a signal for timing advance adjustment transmitted        from the another terminal device, and    -   controls the first transmission timing related to the data        transmission to the another terminal device based on the first        communication by performing control so that notification of the        timing advance value is provided to the another terminal device.

(28)

The communication device according to the above (26), in which thecontrol unit

performs frame synchronization with the another terminal device on thebasis of a reception result of a predetermined signal, and

-   -   controls the first transmission timing related to the data        transmission to the another terminal device based on the first        communication by performing control so that the signal for        timing advance adjustment is transmitted to the another terminal        device at a timing according to a result of the frame        synchronization.

(29)

The communication device according to the above (25),

in which the communication device is a terminal device, and

the control unit controls the first transmission timing related to datatransmission by another terminal device based on the firstcommunication.

(30)

The communication device according to the above (25),

in which the communication device is a base station, and

the control unit controls the first transmission timing related to datatransmission to a second terminal device by a first terminal devicebased on the first communication.

(31)

A communication method executed by a computer, including:

performing wireless communication; and

independently controlling a first transmission timing of firstcommunication with destination designation and a second transmissiontiming of second communication without destination designation amonginter-device communication between different terminal devices.

(32)

A program for causing a computer to execute the following steps of:

performing wireless communication; and

independently controlling a first transmission timing of firstcommunication with destination designation and a second transmissiontiming of second communication without destination designation amonginter-device communication between different terminal devices.

REFERENCE SIGNS LIST

-   1 Base station device-   101 Upper layer processing unit-   103 Control unit-   105 Reception unit-   1051 Decoding unit-   1053 Demodulating unit-   1055 Demultiplexing unit-   1057 Wireless receiving unit-   1059 Channel measuring unit-   107 Transmission unit-   1071 Coding unit-   1073 Modulating unit-   1075 Multiplexing unit-   1077 Wireless transmitting unit-   1079 Link reference signal generating unit-   109 Transmission/reception antenna-   2 Terminal device-   201 Upper layer processing unit-   203 Control unit-   205 Reception unit-   2051 Decoding unit-   2053 Demodulating unit-   2055 Demultiplexing unit-   2057 Wireless receiving unit-   2059 Channel measuring unit-   207 Transmission unit-   2071 Coding unit-   2073 Modulating unit-   2075 Multiplexing unit-   2077 Wireless transmitting unit-   2079 Link reference signal generating unit-   209 Transmission/reception antenna

The invention claimed is:
 1. A communication device comprising: atransceiver that performs wireless communication; and circuitryconfigured to arrange a plurality of synchronization signals in apattern according to regions to which resources of the wirelesscommunication are allocated and is transmitted to another terminaldevice, the plurality of synchronization signals being associated witheach of a plurality of beams allocated to be available for inter-devicecommunication between different terminal devices, and switch the patternof the plurality of synchronization signals to a different pattern inresponse to an occurrence of a predetermined condition.
 2. Thecommunication device according to claim 1, wherein the circuitry isconfigured to control the transceiver to notify the another terminaldevice of the different pattern.
 3. The communication device accordingto claim 2, wherein the circuitry is configured to control thetransceiver to notify the another terminal device after the pattern isswitched to the different pattern.
 4. The communication device accordingto claim 2, wherein the circuitry is further configured to switch thepattern to the different pattern at a predetermined timing, and controlthe transceiver to notify another terminal device prior to the anotherterminal device receiving the different pattern.
 5. The communicationdevice according to claim 2, wherein information regarding the differentpattern provided by the transceiver includes at least one of informationregarding a beam associated with each of the plurality ofsynchronization signals, information regarding a terminal device of atransmission source, or information regarding a number ofsynchronization signals transmitted in one cycle.
 6. The communicationdevice according to claim 2, wherein information regarding the differentpattern is provided by the transceiver as a bitmap.
 7. The communicationdevice according to claim 1, wherein the circuitry is configured toswitch the pattern in response to receiving an instruction from anothercommunication device.
 8. The communication device according to claim 7,wherein the another communication device is a base station.
 9. Thecommunication device according to claim 7, wherein the anothercommunication device is another terminal device having authorityregarding control of the inter-device communication.
 10. Thecommunication device according to claim 1, wherein the circuitry isconfigured to switch the pattern in response to receiving a request fromthe another terminal device.
 11. The communication device according toclaim 10, wherein the circuitry is configured to switch the pattern inresponse to a reception timing of the another terminal device in theinter-device communication.
 12. The communication device according toclaim 1, wherein the circuitry is configured to set a plurality ofsynchronization signal sets with which the plurality of synchronizationsignals is associated, respectively, and perform control so that thepattern in which the plurality of synchronization signals is arranged isswitched by switching a synchronization signal set used for transmittingthe plurality of synchronization signals to the another terminal device.13. The communication device according to claim 1, wherein a timingadvance value for the another terminal device to designate a destinationand transmit data by the inter-device communication is calculated on abasis of a synchronization signal selected by the another terminaldevice among the plurality of synchronization signals.
 14. Thecommunication device according to claim 13, wherein the circuitry isconfigured to perform control so that a signal for timing advanceadjustment corresponding to the synchronization signal selected by theanother terminal device is received from the another terminal device,and perform control so that notification of the timing advance valueaccording to a reception result of the signal for timing advanceadjustment is provided to the another terminal device.
 15. Thecommunication device according to claim 13, wherein the circuitry isconfigured to perform frame synchronization with the another terminaldevice on a basis of a reception result of a predetermined signal, andperform control so a signal for timing advance adjustment is transmittedto the another terminal device as the synchronization signal at a timingaccording to a result of the frame synchronization, and the timingadvance value is calculated on a basis of a reception result of thesignal for timing advance adjustment by the another terminal device. 16.The communication device according to claim 15, wherein the circuitry isconfigured to perform control so that the frame synchronization isperformed on a basis of at least one of a global navigation satellitesystem (GNSS) signal, a downlink signal transmitted from a base station,or a signal transmitted from a terminal device having authorityregarding control of the inter-device communication.
 17. Thecommunication device according to claim 1, wherein the circuitry isconfigured to control a number of the plurality of synchronizationsignals according to a predetermined condition when the pattern isswitched.
 18. The communication device according to claim 1, wherein thecircuitry is configured to control allocation of resources for theanother terminal device to transmit data via the inter-devicecommunication.
 19. A communication method comprising: performingwireless communication with a transceiver having a controller;arranging, with the controller, a plurality of synchronization signalsin a pattern according to regions to which resources of the wirelesscommunication are allocated; transmitting the synchronization signals toanother terminal device, the plurality of synchronization signals beingassociated with each of a plurality of beams allocated to be availablefor inter-device communication between different terminal devices; andaccording to a predetermined condition, switching the pattern of theplurality of synchronization signals to a different pattern.
 20. Anon-transitory computer readable storage device having stored thereincomputer-readable instructions that when executed by a processor causethe processor to execute a method, the method comprising: performingwireless communication with a transceiver; arranging a plurality ofsynchronization signals in a pattern according to regions to whichresources of the wireless communication are allocated; transmitting thesynchronization signals to another terminal device, the plurality ofsynchronization signals being associated with each of a plurality ofbeams allocated to be available for inter-device communication betweendifferent terminal devices; and according to a predetermined condition,switching the pattern of the plurality of synchronization signals to adifferent pattern.